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|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
18,400 |
0807.4586
|
Andrew Downes
|
Andrew N. Downes
|
Bounds for the Transition Density of Time-Homogeneous Diffusion
Processes
|
14 pages, 5 figures
| null | null | null |
math.PR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The paper presents new simple sharp bounds for transition density functions
for time-homogeneous diffusions processes. The bounds are obtained under mild
conditions on the drift and diffusion coefficients, extending and substantially
improving previous results in the literature which were limited to drifts
satisfying a linear growth condition. They lead to an asymptotic expression for
the transition density as the transition time approaches zero. While the focus
is on the one-dimensional case, an extension to multiple dimensions is
discussed. Results are illustrated by numerical examples.
|
[{'version': 'v1', 'created': 'Tue, 29 Jul 2008 07:22:51 GMT'}]
|
2008-12-08
|
[array(['Downes', 'Andrew N.', ''], dtype=object)]
|
18,401 |
1902.03681
|
Wim Cosyn
|
W. Cosyn, B. Pire
|
Deuteron helicity flip generalized parton distributions in a convolution
model
|
4 pages, 2 figures; Proceedings of 8th International Conference on
Quarks and Nuclear Physics (QNP2018) 13-17 Nov 2018; Tsukuba, Japan
| null |
10.7566/JPSCP.26.021005
|
CPHT-PC003.022019
|
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the general properties of generalized parton distributions with
helicity flip (transversity) for spin-1 hadrons in the leading twist case.
Using a basic light cone convolution model, we show the deuteron helicity
amplitudes containing quark helicity flip GPDs and comment on the role deuteron
angular momentum plays in these.
|
[{'version': 'v1', 'created': 'Sun, 10 Feb 2019 23:01:38 GMT'}]
|
2020-01-08
|
[array(['Cosyn', 'W.', ''], dtype=object)
array(['Pire', 'B.', ''], dtype=object)]
|
18,402 |
gr-qc/9906017
|
Marco Bruni
|
Marco Bruni (Cardiff University, UK) and Sebastiano Sonego
(Universita` di Udine, Italy)
|
Observables and gauge invariance in the theory of non-linear spacetime
perturbations
|
8 pages, LaTeX, CQG style. Classical and Quantum Gravity, Letters to
the Editor, in press
|
Class.Quant.Grav.16:L29-L36,1999
|
10.1088/0264-9381/16/7/101
| null |
gr-qc astro-ph hep-th
| null |
We discuss the issue of observables in general-relativistic perturbation
theory, adopting the view that any observable in general relativity is
represented by a scalar field on spacetime. In the context of perturbation
theory, an observable is therefore a scalar field on the perturbed spacetime,
and as such is gauge invariant in an exact sense (to all orders), as one would
expect. However, perturbations are usually represented by fields on the
background spacetime, and expanded at different orders into contributions that
may or may not be gauge independent. We show that perturbations of scalar
quantities are observable if they are first order gauge-invariant, even if they
are gauge dependent at higher order. Gauge invariance to first order plays
therefore an important conceptual role in the theory, for it selects the
perturbations with direct physical meaning from those having only a
mathematical status. The so-called ``gauge problem'', and the relationship
between measured fluctuations and gauge dependent perturbations that are
computed in the theory are also clarified.
|
[{'version': 'v1', 'created': 'Fri, 4 Jun 1999 18:18:02 GMT'}]
|
2010-04-06
|
[array(['Bruni', 'Marco', '', 'Cardiff University, UK'], dtype=object)
array(['Sonego', 'Sebastiano', '', 'Universita` di Udine, Italy'],
dtype=object) ]
|
18,403 |
2301.13442
|
Jacob Hilton
|
Jacob Hilton, Jie Tang, John Schulman
|
Scaling laws for single-agent reinforcement learning
|
33 pages
| null | null | null |
cs.LG cs.AI stat.ML
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recent work has shown that, in generative modeling, cross-entropy loss
improves smoothly with model size and training compute, following a power law
plus constant scaling law. One challenge in extending these results to
reinforcement learning is that the main performance objective of interest, mean
episode return, need not vary smoothly. To overcome this, we introduce
*intrinsic performance*, a monotonic function of the return defined as the
minimum compute required to achieve the given return across a family of models
of different sizes. We find that, across a range of environments, intrinsic
performance scales as a power law in model size and environment interactions.
Consequently, as in generative modeling, the optimal model size scales as a
power law in the training compute budget. Furthermore, we study how this
relationship varies with the environment and with other properties of the
training setup. In particular, using a toy MNIST-based environment, we show
that varying the "horizon length" of the task mostly changes the coefficient
but not the exponent of this relationship.
|
[{'version': 'v1', 'created': 'Tue, 31 Jan 2023 06:38:53 GMT'}
{'version': 'v2', 'created': 'Sun, 19 Feb 2023 01:24:51 GMT'}]
|
2023-02-21
|
[array(['Hilton', 'Jacob', ''], dtype=object)
array(['Tang', 'Jie', ''], dtype=object)
array(['Schulman', 'John', ''], dtype=object)]
|
18,404 |
1404.2077
|
Xihua Zou
|
Xihua Zou, Wangzhe Li, Bing Lu, Wei Pan, Lianshan Yan, and Liyang Shao
|
Wide-open, high-resolution microwave/millimeter-wave Doppler frequency
shift estimation using photonics technology
|
8 pages, 10 figures
| null | null | null |
physics.optics
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Today, wide-open, high-resolution Doppler frequency shift (DFS) estimation is
essential for radar, microwave/millimeter-wave, and communication systems.
Using photonics technology, an effective approach is proposed and
experimentally demonstrated, providing a high-resolution and
frequency-independent solution. In the approach consisting of two cascaded
opto-electronic modulators, DFS between the transmitted microwave/
millimeter-wave signal and the received echo signal is mapped into a doubled
spacing between two target optical sidebands. Subsequently, the DFS is then
estimated through the spectrum analysis of a generated low-frequency electrical
signal, with an improved resolution by a factor of 2. In experiments, DFSs from
-90 to 90 KHz are successfully estimated for microwave/millimeter-wave signals
at 10, 15, and 30 GHz, where estimation errors keep lower than +/- 5e-10 Hz.
For radial velocity measurement, these results reveal a range from 0 to 900 m/s
(0 to 450 m/s) and a resolution of 1e-11 m/s (5e-12 m/s) at 15-GHz (30-GHz)
frequency band.
|
[{'version': 'v1', 'created': 'Tue, 8 Apr 2014 10:25:18 GMT'}]
|
2014-04-09
|
[array(['Zou', 'Xihua', ''], dtype=object)
array(['Li', 'Wangzhe', ''], dtype=object)
array(['Lu', 'Bing', ''], dtype=object)
array(['Pan', 'Wei', ''], dtype=object)
array(['Yan', 'Lianshan', ''], dtype=object)
array(['Shao', 'Liyang', ''], dtype=object)]
|
18,405 |
2201.03831
|
Olivier Cots
|
Bernard Bonnard (IMB, McTAO), Olivier Cots (IRIT-APO, Toulouse INP),
Joseph Gergaud (IRIT-APO, Toulouse INP), Boris Wembe (UT3)
|
Abnormal Geodesics in 2D-Zermelo Navigation Problems in the Case of
Revolution and the Fan Shape of the Small Time Balls
|
Systems and Control Letters, Elsevier, In press
| null | null | null |
math.DG
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this article, based on two case studies, we discuss the role of abnormal
geodesics in planar Zermelo navigation problems. Such curves are limit curves
of the accessibility set, in the domain where the current is strong. The
problem is set in the frame of geometric time optimal control, where the
control is the heading angle of the ship and in this context, abnormal curves
are shown to separate time minimal curves from time maximal curves and are both
small-time minimizing and maximizing. We describe the small-time minimal balls.
For bigger time, a cusp singularity can occur in the abnormal direction, which
corresponds to a conjugate point along the non-smooth image. It is interpreted
in terms of the regularity property of the time minimal value function.
|
[{'version': 'v1', 'created': 'Tue, 11 Jan 2022 08:23:23 GMT'}]
|
2022-01-12
|
[array(['Bonnard', 'Bernard', '', 'IMB, McTAO'], dtype=object)
array(['Cots', 'Olivier', '', 'IRIT-APO, Toulouse INP'], dtype=object)
array(['Gergaud', 'Joseph', '', 'IRIT-APO, Toulouse INP'], dtype=object)
array(['Wembe', 'Boris', '', 'UT3'], dtype=object)]
|
18,406 |
2002.05157
|
Maria Mongui\'o
|
M. Mongui\'o, R. Greimel, J. E. Drew, G. Barentsen, P. J. Groot, M. J.
Irwin, J. Casares, B. T.G\"ansicke, P. J. Carter, J. M. Corral-Santana, N. P.
Gentile-Fusillo, S. Greiss, L. M. van Haaften, M. Hollands, D. Jones, T.
Kupfer, C. J. Manser, D. N. A. Murphy, A. F. McLeod, T. Oosting, Q. A.
Parker, S. Pyrzas, P. Rodr\'iguez-Gil, J. van Roestel, S. Scaringi, P.
Schellart, O. Toloza, O. Vaduvescu, L. van Spaandonk, K. Verbeek, N. J.
Wright, J. Eisl\"offel, J. Fabregat, A. Harris, R. A. H. Morris, S.
Phillipps, R. Raddi, L. Sabin, Y. Unruh, J. S Vink, R. Wesson, A. Cardwell,
R. K.Cochrane, S. Doostmohammadi, T. Mocnik, H. Stoev, L. Su\'arez-Andr\'es,
V. Tudor, T. G. Wilson and T. J. Zegmott
|
IGAPS: the merged IPHAS and UVEX optical surveys of theNorthern Galactic
Plane
|
28 pages, 22 figures
|
A&A 638, A18 (2020)
|
10.1051/0004-6361/201937333
| null |
astro-ph.IM astro-ph.GA astro-ph.SR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The INT Galactic Plane Survey (IGAPS) is the merger of the optical
photometric surveys, IPHAS and UVEX, based on data from the Isaac Newton
Telescope (INT) obtained between 2003 and 2018. Here, we present the IGAPS
point source catalogue. It contains 295.4 million rows providing photometry in
the filters, i, r, narrow-band Halpha, g and U_RGO. The IGAPS footprint fills
the Galactic coordinate range, |b| < 5deg and 30deg < l < 215deg. A uniform
calibration, referred to the Pan-STARRS system, is applied to g, r and i, while
the Halpha calibration is linked to r and then is reconciled via field
overlaps. The astrometry in all 5 bands has been recalculated on the Gaia DR2
frame. Down to i ~ 20 mag (Vega system), most stars are also detected in g, r
and Halpha. As exposures in the r band were obtained within the IPHAS and UVEX
surveys a few years apart, typically, the catalogue includes two distinct r
measures, r_I and r_U. The r 10sigma limiting magnitude is ~21, with median
seeing 1.1 arcsec. Between ~13th and ~19th magnitudes in all bands, the
photometry is internally reproducible to within 0.02 magnitudes. Stars brighter
than r=19.5 have been tested for narrow-band Halpha excess signalling line
emission, and for variation exceeding |r_I-r_U| = 0.2 mag. We find and flag
8292 candidate emission line stars and over 53000 variables (both at >5sigma
confidence). The 174-column catalogue will be available via CDS Strasbourg.
|
[{'version': 'v1', 'created': 'Wed, 12 Feb 2020 18:59:50 GMT'}]
|
2020-07-01
|
[array(['Monguió', 'M.', ''], dtype=object)
array(['Greimel', 'R.', ''], dtype=object)
array(['Drew', 'J. E.', ''], dtype=object)
array(['Barentsen', 'G.', ''], dtype=object)
array(['Groot', 'P. J.', ''], dtype=object)
array(['Irwin', 'M. J.', ''], dtype=object)
array(['Casares', 'J.', ''], dtype=object)
array(['Gänsicke', 'B. T.', ''], dtype=object)
array(['Carter', 'P. J.', ''], dtype=object)
array(['Corral-Santana', 'J. M.', ''], dtype=object)
array(['Gentile-Fusillo', 'N. P.', ''], dtype=object)
array(['Greiss', 'S.', ''], dtype=object)
array(['van Haaften', 'L. M.', ''], dtype=object)
array(['Hollands', 'M.', ''], dtype=object)
array(['Jones', 'D.', ''], dtype=object)
array(['Kupfer', 'T.', ''], dtype=object)
array(['Manser', 'C. J.', ''], dtype=object)
array(['Murphy', 'D. N. A.', ''], dtype=object)
array(['McLeod', 'A. F.', ''], dtype=object)
array(['Oosting', 'T.', ''], dtype=object)
array(['Parker', 'Q. A.', ''], dtype=object)
array(['Pyrzas', 'S.', ''], dtype=object)
array(['Rodríguez-Gil', 'P.', ''], dtype=object)
array(['van Roestel', 'J.', ''], dtype=object)
array(['Scaringi', 'S.', ''], dtype=object)
array(['Schellart', 'P.', ''], dtype=object)
array(['Toloza', 'O.', ''], dtype=object)
array(['Vaduvescu', 'O.', ''], dtype=object)
array(['van Spaandonk', 'L.', ''], dtype=object)
array(['Verbeek', 'K.', ''], dtype=object)
array(['Wright', 'N. J.', ''], dtype=object)
array(['Eislöffel', 'J.', ''], dtype=object)
array(['Fabregat', 'J.', ''], dtype=object)
array(['Harris', 'A.', ''], dtype=object)
array(['Morris', 'R. A. H.', ''], dtype=object)
array(['Phillipps', 'S.', ''], dtype=object)
array(['Raddi', 'R.', ''], dtype=object)
array(['Sabin', 'L.', ''], dtype=object)
array(['Unruh', 'Y.', ''], dtype=object)
array(['Vink', 'J. S', ''], dtype=object)
array(['Wesson', 'R.', ''], dtype=object)
array(['Cardwell', 'A.', ''], dtype=object)
array(['Cochrane', 'R. K.', ''], dtype=object)
array(['Doostmohammadi', 'S.', ''], dtype=object)
array(['Mocnik', 'T.', ''], dtype=object)
array(['Stoev', 'H.', ''], dtype=object)
array(['Suárez-Andrés', 'L.', ''], dtype=object)
array(['Tudor', 'V.', ''], dtype=object)
array(['Wilson', 'T. G.', ''], dtype=object)
array(['Zegmott', 'T. J.', ''], dtype=object)]
|
18,407 |
0710.4075
|
Michael Noble S.
|
Michael S. Noble
|
Getting More From Your Multicore: Exploiting OpenMP for Astronomy
|
4 pages, 4 figures Conference proceedings for ADASS07, London
| null | null | null |
astro-ph
| null |
Motivated by the emergence of multicore architectures, and the reality that
parallelism is rarely used for analysis in observational astronomy, we
demonstrate how general users may employ tightly-coupled multiprocessors in
scriptable research calculations while requiring no special knowledge of
parallel programming. Our method rests on the observation that much of the
appeal of high-level vectorized languages like IDL or MatLab stems from
relatively simple internal loops over regular array structures, and that these
loops are highly amenable to automatic parallelization with OpenMP. We discuss
how ISIS, an open-source astrophysical analysis system embedding the S-Lang
numerical language, was easily adapted to exploit this pattern. Drawing from a
common astrophysical problem, model fitting, we present beneficial speedups for
several machine and compiler configurations. These results complement our
previous efforts with PVM, and together lead us to believe that ISIS is the
only general purpose spectroscopy system in which such a range of parallelism
-- from single processors on multiple machines to multiple processors on single
machines -- has been demonstrated.
|
[{'version': 'v1', 'created': 'Mon, 22 Oct 2007 14:31:44 GMT'}]
|
2007-10-23
|
[array(['Noble', 'Michael S.', ''], dtype=object)]
|
18,408 |
cond-mat/0512500
|
Doron Cohen
|
Itamar Sela and Doron Cohen
|
Operating a quantum pump in a closed circuit
|
19 pages, 8 figs, minor textual corretions, to be published in JPA
|
J. Phys. A 39, 3575 (2006)
|
10.1088/0305-4470/39/14/006
| null |
cond-mat.mes-hall
| null |
During an adiabatic pumping cycle a conventional two barrier quantum device
takes an electron from the left lead and ejects it to the right lead. Hence the
pumped charge per cycle is naively expected to be $Q \le e$. This zero order
adiabatic point of view is in fact misleading. For a closed device we can get
${Q > e}$ and even ${Q \gg e}$. In this paper a detailed analysis of the
quantum pump operation is presented. Using the Kubo formula for the geometric
conductance, and applying the Dirac chains picture, we derive practical
estimates for~$Q$.
|
[{'version': 'v1', 'created': 'Tue, 20 Dec 2005 12:58:36 GMT'}
{'version': 'v2', 'created': 'Sun, 5 Feb 2006 13:23:38 GMT'}
{'version': 'v3', 'created': 'Wed, 22 Feb 2006 06:06:37 GMT'}]
|
2009-11-11
|
[array(['Sela', 'Itamar', ''], dtype=object)
array(['Cohen', 'Doron', ''], dtype=object)]
|
18,409 |
0908.3237
|
Sangeeta Chakrabarti
|
Sangeeta Chakrabarti, S. Anantha Ramakrishna and Harshawardhan Wanare
|
Switching a plasma-like metamaterial via embedded resonant atoms
exhibiting electromagnetically induced transparency
|
9 pages, 3 figures
|
Optics Letters, 34, 3728 (2009)
|
10.1364/OL.34.003728
| null |
physics.optics
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We theoretically demonstrate control of the plasma-like effective response of
a metamaterial composed of aligned metallic nanorods when the electric field of
the incident radiation is parallel to the nanorods. By embedding this
metamaterial in a coherent atomic/molecular medium, for example silver nanorod
arrays submerged in sodium vapor, we can make the metamaterial transmittive in
the forbidden frequency region below its plasma frequency. This phenomenon is
enabled by having Lorentz absorbers or other coherent processes like stimulated
Raman absorption in the background medium which provide a large positive
dielectric permittivity in the vicinity of the resonance, thereby rendering the
effective permittivity positive. In particular, processes such as
electromagnetically induced transparency are shown to provide additional
control to switch and tune the new transmission bands.
|
[{'version': 'v1', 'created': 'Sat, 22 Aug 2009 07:40:54 GMT'}]
|
2015-05-14
|
[array(['Chakrabarti', 'Sangeeta', ''], dtype=object)
array(['Ramakrishna', 'S. Anantha', ''], dtype=object)
array(['Wanare', 'Harshawardhan', ''], dtype=object)]
|
18,410 |
1308.0470
|
Ramaseshan Rajagopalan
|
S.Tripura Sundari, R.Ramaseshan, Feby Jose, S.Dash, A.K.Tyagi
|
Temperature dependence of dielectric constants in Titanium Nitride
|
12 pages, 7 figures
| null | null | null |
cond-mat.mtrl-sci
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The temperature dependence of optical constants of titanium nitride thin film
is investigated using spectroscopic ellipsometry between 1.4 to 5 eV in the
temperature range 300 K to 650 K in steps of 50 K. The real and imaginary parts
of the dielectric functions "1(E) and "2(E) increase marginally with increase
in temperature. A Drude Lorentz dielectric analysis based on free electron and
oscillator model are carried out to describe the temperature behavior. The
parameters of the Lorentz oscillator model also showed that the relaxation time
decreased with temperature while the oscillator energies increased. This study
shows that owing to marginal change in the refractive index with temperature,
titanium nitride can be employed for surface plasmon sensor applications even
in environments where rise in temperature is imminent.
|
[{'version': 'v1', 'created': 'Fri, 2 Aug 2013 11:28:32 GMT'}]
|
2016-11-26
|
[array(['Sundari', 'S. Tripura', ''], dtype=object)
array(['Ramaseshan', 'R.', ''], dtype=object)
array(['Jose', 'Feby', ''], dtype=object)
array(['Dash', 'S.', ''], dtype=object)
array(['Tyagi', 'A. K.', ''], dtype=object)]
|
18,411 |
1607.06724
|
Matthew Reuter
|
Matthew G. Reuter
|
A Unified Perspective of Complex Band Structure: Interpretations,
Formulations, and Applications
|
50 pages, 4 figures
|
J. Phys.: Condens. Matter, 29, 053001 (2017)
|
10.1088/1361-648X/29/5/053001
| null |
cond-mat.mtrl-sci
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Complex band structure generalizes conventional band structure by also
considering wavevectors with complex components. In this way, complex band
structure describes both the bulk-propagating states from conventional band
structure and the evanescent states that grow or decay from one unit cell to
the next. Even though these latter states are excluded by translational
symmetry, they become important when translational symmetry is broken via, for
example, a surface or impurity.
Many studies over the last 80 years have directly or indirectly developed
complex band structure for an impressive range of applications, but very few
discuss its fundamentals or compare its various results. In this work we build
upon these previous efforts to expose the physical foundation of complex band
structure, which mathematically implies the existence of complex band
structure. We find that a material's static and dynamic electronic structure
are both completely described by complex band structure. Furthermore, we show
that complex band structure reflects the minimal, intrinsic information
contained in the material's Hamiltonian. These realizations then provide a
context for discussing, comparing, and unifying the different formulations and
applications of complex band structure that have been developed over the years.
Ultimately, this discussion introduces the idea of examining the amount of
information contained in a material's Hamiltonian so that we can find and
exploit the minimal information necessary for understanding a material's
properties.
|
[{'version': 'v1', 'created': 'Fri, 22 Jul 2016 16:12:25 GMT'}]
|
2017-07-20
|
[array(['Reuter', 'Matthew G.', ''], dtype=object)]
|
18,412 |
2106.03830
|
Sascha Rothe
|
Sascha Rothe, Jonathan Mallinson, Eric Malmi, Sebastian Krause,
Aliaksei Severyn
|
A Simple Recipe for Multilingual Grammatical Error Correction
| null | null | null | null |
cs.CL
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This paper presents a simple recipe to train state-of-the-art multilingual
Grammatical Error Correction (GEC) models. We achieve this by first proposing a
language-agnostic method to generate a large number of synthetic examples. The
second ingredient is to use large-scale multilingual language models (up to 11B
parameters). Once fine-tuned on language-specific supervised sets we surpass
the previous state-of-the-art results on GEC benchmarks in four languages:
English, Czech, German and Russian. Having established a new set of baselines
for GEC, we make our results easily reproducible and accessible by releasing a
cLang-8 dataset. It is produced by using our best model, which we call gT5, to
clean the targets of a widely used yet noisy lang-8 dataset. cLang-8 greatly
simplifies typical GEC training pipelines composed of multiple fine-tuning
stages -- we demonstrate that performing a single fine-tuning step on cLang-8
with the off-the-shelf language models yields further accuracy improvements
over an already top-performing gT5 model for English.
|
[{'version': 'v1', 'created': 'Mon, 7 Jun 2021 17:47:04 GMT'}
{'version': 'v2', 'created': 'Tue, 9 Aug 2022 14:49:30 GMT'}]
|
2022-08-10
|
[array(['Rothe', 'Sascha', ''], dtype=object)
array(['Mallinson', 'Jonathan', ''], dtype=object)
array(['Malmi', 'Eric', ''], dtype=object)
array(['Krause', 'Sebastian', ''], dtype=object)
array(['Severyn', 'Aliaksei', ''], dtype=object)]
|
18,413 |
1208.6564
|
Alexander Mishchenko
|
Alexander S. Mishchenko and XiaoYu Li
|
Comparison of categorical characteristic classes of transitive Lie
algebroid with Chern-Weil homomorphism
|
13 pages
| null | null | null |
math.KT math.AT math.CT
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Transitive Lie algebroids have specific properties that allow to look at the
transitive Lie algebroid as an element of the object of a homotopy functor.
Roughly speaking each transitive Lie algebroids can be described as a vector
bundle over the tangent bundle of the manifold which is endowed with additional
structures. Therefore transitive Lie algebroids admits a construction of
inverse image generated by a smooth mapping of smooth manifolds. Due to to
K.Mackenzie (2005) the construction can be managed as a homotopy functor
$\mathcal{TLA}_{\rg}$ from category of smooth manifolds to the transitive Lie
algebroids. The functor $\mathcal{TLA}_{\rg}$ associates with each smooth
manifold $M$ the set $\mathcal{TLA}_{\rg}(M)$ of all transitive algebroids with
fixed structural finite dimensional Lie algebra $\rg$. Hence one can construct
a classifying space $\cB_{\rg}$ such that the family of all transitive Lie
algebroids with fixed Lie algebra $\rg$ over the manifold $M$ has one-to-one
correspondence with the family of homotopy classes of continuous maps
$[M,\cB_{\rg}]$: $\mathcal{TLA}_{\rg}(M)\approx [M,\cB_{\rg}].$
It allows to describe characteristic classes of transitive Lie algebroids
from the point of view a natural transformation of functors similar to the
classical abstract characteristic classes for vector bundles and to compare
them with that derived from the Chern-Weil homomorphism by J.Kubarski. As a
matter of fact we show that the Chern-Weil homomorphism does not cover all
characteristic classes from categorical point of view.
|
[{'version': 'v1', 'created': 'Fri, 31 Aug 2012 18:08:49 GMT'}]
|
2012-09-03
|
[array(['Mishchenko', 'Alexander S.', ''], dtype=object)
array(['Li', 'XiaoYu', ''], dtype=object)]
|
18,414 |
2006.12507
|
Alessandro Savino
|
A. Savino, A. Koch, Z. Prudil, A. Kunder and R. Smolec
|
The age of the Milky Way inner stellar spheroid from RR Lyrae population
synthesis
|
Accepted for publication in Astronomy & Astrophysics. 17 pages, 15
figures
|
A&A 641, A96 (2020)
|
10.1051/0004-6361/202038305
| null |
astro-ph.GA astro-ph.SR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The central kiloparsecs of the Milky Way are known to host an old, spheroidal
stellar population, whose spatial and kinematical properties set it apart from
the boxy/peanut structure that constitutes most of the central stellar mass.
The nature of this spheroidal population, whether a small classical bulge, the
innermost stellar halo or a population of disk stars with large initial
velocity dispersion, remains unclear. This structure is also a promising
candidate to host some of the oldest stars in the Galaxy. Here we address the
topic of the inner stellar spheroid age, using spectroscopic and photometric
metallicities for a sample of 935 RR Lyrae stars that are constituents of this
component. By means of stellar population synthesis, we derive an
age-metallicity relation for RR Lyrae populations. We infer, for the RR Lyrae
stars in the bulge spheroid, an extremely ancient age of $13.41 \pm 0.54$ Gyr
and conclude they were among the first stars to form in what is now the Milky
Way galaxy. Our age estimate for the central spheroid shows remarkable
agreement with the age profile that has been inferred for the Milky Way stellar
halo, suggesting a connection between the two structures. However, we find mild
evidence for a transition in the halo properties at $r_{\rm GC} \sim 5$~kpc. We
also investigate formation scenarios for metal-rich RR Lyrae stars, such as
binarity and helium variations, and whether they can provide alternative
explanations for the properties of our sample. We conclude that, within our
framework, the only viable alternative is to have younger, slightly
helium-rich, RR Lyrae stars, a hypothesis that would open intriguing questions
for the formation of the inner stellar spheroid.
|
[{'version': 'v1', 'created': 'Mon, 22 Jun 2020 18:00:01 GMT'}]
|
2020-09-16
|
[array(['Savino', 'A.', ''], dtype=object)
array(['Koch', 'A.', ''], dtype=object)
array(['Prudil', 'Z.', ''], dtype=object)
array(['Kunder', 'A.', ''], dtype=object)
array(['Smolec', 'R.', ''], dtype=object)]
|
18,415 |
1801.07884
|
Zhiqiang Wei
|
Zhiqiang Wei and Derrick Wing Kwan Ng and Jinhong Yuan
|
Joint Pilot and Payload Power Control for Uplink MIMO-NOMA with MRC-SIC
Receivers
|
4 pages, 4 figures, accepted in IEEE Communications Letters
| null | null | null |
cs.IT math.IT
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This letter proposes a joint pilot and payload power allocation (JPA) scheme
to mitigate the error propagation problem for uplink multiple-input
multiple-output non-orthogonal multiple access (MIMO-NOMA) systems. A base
station equipped with a maximum ratio combining and successive interference
cancellation (MRC-SIC) receiver is adopted for multiuser detection. The average
signal-to-interference-plus-noise ratio (ASINR) of each user during the MRC-SIC
decoding is analyzed by taking into account the error propagation due to the
channel estimation error. Furthermore, the JPA design is formulated as a
nonconvex optimization problem to maximize the minimum weighted ASINR and is
solved optimally with geometric programming. Simulation results confirm the
developed performance analysis and show that our proposed scheme can
effectively alleviate the error propagation of MRC-SIC and enhance the
detection performance, especially for users with moderate energy budgets.
|
[{'version': 'v1', 'created': 'Wed, 24 Jan 2018 07:32:32 GMT'}]
|
2018-01-25
|
[array(['Wei', 'Zhiqiang', ''], dtype=object)
array(['Ng', 'Derrick Wing Kwan', ''], dtype=object)
array(['Yuan', 'Jinhong', ''], dtype=object)]
|
18,416 |
1701.04111
|
Pronob Mitter
|
P. K. Mitter
|
On A Finite Range Decomposition of the Resolvent of a Fractional Power
of the Laplacian II. The Torus
|
17 pages
| null |
10.1007/s10955-017-1828-5
| null |
math-ph math.MP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In previous papers, [M1, M2], [M3], we proved the existence as well as
regularity of a finite range decomposition for the resolvent $G_{\alpha}
(x-y,m^2) = ((-\Delta)^{\alpha\over 2} + m^{2})^{-1} (x-y) $, for $0<\alpha <2$
and all real $m$, in the lattice ${\bf Z}^{d}$ for dimension $d\ge 2$. In this
paper, which is a continuation of the previous one, we extend those results by
proving the existence as well as regularity of a finite range decomposition for
the same resolvent but now on the lattice torus ${\bf Z}^{d}/L^{N+1}{\bf Z}^{d}
$ for $d\ge 2$ provided $m\neq 0$ and $0<\alpha <2$. We also prove
differentiability and uniform continuity properties with respect to the
resolvent parameter $m^{2}$. Here $L$ is any odd positive integer and $N\ge 2$
is any positive integer.
|
[{'version': 'v1', 'created': 'Sun, 15 Jan 2017 21:03:37 GMT'}
{'version': 'v2', 'created': 'Fri, 26 May 2017 14:23:12 GMT'}]
|
2017-08-02
|
[array(['Mitter', 'P. K.', ''], dtype=object)]
|
18,417 |
1807.07451
|
Eoin \'O Colg\'ain
|
Eoin \'O Colg\'ain, Maurice H. P. M. van Putten, Hossein Yavartanoo
|
de Sitter Swampland, $H_0$ tension & observation
|
v1 4 pages, comments welcome; v2 replacing mistakenly uploaded
unfinished version; v3 arguments revised; v4; v5 matches published version,
further changes outcome of the review process
| null |
10.1016/j.physletb.2019.04.032
| null |
hep-th astro-ph.CO gr-qc
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Realising de Sitter vacua in string theory is challenging. For this reason it
has been conjectured that de Sitter vacua inhabit the Swampland of inconsistent
low-energy effective theories coupled to gravity. Since de Sitter is an
attractor for $\Lambda$CDM, the conjecture calls $\Lambda$CDM into question.
Reality appears sympathetic to this idea as local measurements of the Hubble
constant $H_0$ are also at odds with $\Lambda$CDM analysis of Planck data. This
tension suggests that the de Sitter state is unstable, thereby implying a
turning point in the Hubble parameter. We present a model relieving this
tension, which predicts a turning at small positive redshift $z_*$ that is
dictated by present-day matter density $\omega_m$. This feature is easily
identified by homogeneous surveys covering redshifts $z \leq 0.1$. We comment
on the implications for the Swampland program.
|
[{'version': 'v1', 'created': 'Thu, 19 Jul 2018 14:09:51 GMT'}
{'version': 'v2', 'created': 'Fri, 20 Jul 2018 00:44:41 GMT'}
{'version': 'v3', 'created': 'Thu, 9 Aug 2018 12:16:20 GMT'}
{'version': 'v4', 'created': 'Mon, 5 Nov 2018 08:45:40 GMT'}
{'version': 'v5', 'created': 'Mon, 22 Apr 2019 00:50:05 GMT'}]
|
2019-04-24
|
[array(['Colgáin', 'Eoin Ó', ''], dtype=object)
array(['van Putten', 'Maurice H. P. M.', ''], dtype=object)
array(['Yavartanoo', 'Hossein', ''], dtype=object)]
|
18,418 |
0908.0086
|
Amanda Turner
|
Fredrik Johansson, Alan Sola, Amanda Turner
|
Scaling limits of anisotropic Hastings-Levitov clusters
|
31 pages, 5 figures
|
Annales de l'Institut Henri Poincar\'e - Probabilit\'es et
Statistiques 2012, Vol. 48, No. 1, 235-257
|
10.1214/10-AIHP395
| null |
math.PR math-ph math.CV math.MP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a variation of the standard Hastings-Levitov model HL(0), in
which growth is anisotropic. Two natural scaling limits are established and we
give precise descriptions of the effects of the anisotropy. We show that the
limit shapes can be realised as Loewner hulls and that the evolution of
harmonic measure on the cluster boundary can be described by the solution to a
deterministic ordinary differential equation related to the Loewner equation.
We also characterise the stochastic fluctuations around the deterministic limit
flow.
|
[{'version': 'v1', 'created': 'Mon, 3 Aug 2009 14:59:49 GMT'}]
|
2012-03-12
|
[array(['Johansson', 'Fredrik', ''], dtype=object)
array(['Sola', 'Alan', ''], dtype=object)
array(['Turner', 'Amanda', ''], dtype=object)]
|
18,419 |
astro-ph/0301207
|
Tomaz Zwitter
|
Tomaz Zwitter (1), Arne Henden (2) ((1) University of Ljubljana,
Ljubljana, Slovenia; (2) Universities Space Research Association, Flagstaff,
Arizona)
|
Crowding in the GAIA spectrograph focal plane
|
4 pages, 3 figures; to be published in GAIA spectroscopy, Science and
Technology, ASP Conference Series, U.Munari (ed.)
| null | null | null |
astro-ph
| null |
Superpositions of stellar tracings are present in every slitless
spectrograph. The probability for such overlaps in the GAIA RVS spectrograph
focal plane is estimated using photometric observations of 66 stellar fields,
mostly close to the Galactic plane. It is shown that overlaps of bright stars
(V<17) are common near the Galactic plane, and no spectrum is free from
superpositions of faint star tracings. Most overlappers are of spectral type K.
|
[{'version': 'v1', 'created': 'Mon, 13 Jan 2003 14:43:34 GMT'}]
|
2007-05-23
|
[array(['Zwitter', 'Tomaz', ''], dtype=object)
array(['Henden', 'Arne', ''], dtype=object)]
|
18,420 |
1605.00884
|
Stephanie Bron
|
S. Bron
|
Hyper-Kamiokande: Towards a measurement of CP violation in lepton sector
|
Poster presented at NuPhys2015 (London, 16-18 December 2015). 5
pages, LaTeX
| null | null |
NuPhys2015-Bron
|
hep-ex physics.ins-det
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present the latest Hyper-Kamiokande sensitivity study showing that, with a
total exposure of 13 MW $\times 10^{7}$ seconds integrated beam power, the CP
phase - $\delta_{CP}$ - can be determined better than 21 degrees for all
possible values of $\delta_{CP}$ and CP violation can be established with a
significance of more than 3$\sigma$ (5$\sigma$) for 78% (62%) of the
$\delta_{CP}$ parameter space.
|
[{'version': 'v1', 'created': 'Tue, 3 May 2016 13:01:08 GMT'}
{'version': 'v2', 'created': 'Mon, 22 Aug 2016 15:06:09 GMT'}]
|
2016-08-23
|
[array(['Bron', 'S.', ''], dtype=object)]
|
18,421 |
0810.2155
|
Xavier Calmet
|
X. Calmet, N. G. Deshpande, X. G. He, S. D. H. Hsu
|
Invisible Higgs boson, continuous mass fields and unHiggs mechanism
|
8 pages
|
Phys.Rev.D79:055021,2009
|
10.1103/PhysRevD.79.055021
|
CP3-08-52
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore the consequences of an electroweak symmetry breaking sector which
exhibits approximately scale invariant dynamics -- i.e., nontrivial fixed point
behavior, as in unparticle models. One can think of an unHiggs as a composite
Higgs boson with a continuous mass distribution. We find it convenient to
represent the unHiggs in terms of a Kallen-Lehmann spectral function, from
which it is simple to verify the generation of gauge boson and fermion masses,
and unitarization of WW scattering. We show that a spectral function with broad
support, which corresponds to approximate fixed point behavior over an extended
range of energy, can lead to an effectively invisible Higgs particle, whose
decays at LEP or LHC could be obscured by background.
|
[{'version': 'v1', 'created': 'Mon, 13 Oct 2008 05:15:25 GMT'}
{'version': 'v2', 'created': 'Mon, 27 Oct 2008 19:49:02 GMT'}]
|
2010-04-28
|
[array(['Calmet', 'X.', ''], dtype=object)
array(['Deshpande', 'N. G.', ''], dtype=object)
array(['He', 'X. G.', ''], dtype=object)
array(['Hsu', 'S. D. H.', ''], dtype=object)]
|
18,422 |
2206.09850
|
Zhongyu Wan
|
Zhongyu Wan, Ruiqin Zhang
|
Metallization of hydrogen by intercalating ammonium ions in metal fcc
lattices at low pressure
| null | null |
10.1063/5.0127365
| null |
cond-mat.supr-con
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Metallic hydrogen is capable of showing room temperature superconductivity,
but its experimental syntheses are extremely hard. Therefore, it is desirable
to reduce the synthesis pressure of metallic hydrogen by adding other chemical
elements. However, for most hydrides, the metallization of hydrogen by
"chemical precompression" to achieve high-temperature superconductivity still
requires relatively high pressure, making experimental synthesis difficult. How
to achieve high-temperature superconductivity in the low-pressure range (0-50
GPa) is a key issue for realizing practical applications of superconducting
materials. Toward this end, this work proposes a strategy for inserting
ammonium ions in the fcc crystal of metals. High-throughput calculations of the
periodic table reveal 12 elements which can form kinetically stable and
superconducting hydrides at low pressures, where the highest superconducting
transition temperatures of AlN2H8, MgN2H8 and GaN2H8 can reach up to 118.40,
105.09 and 104.39 K. Pressure-induced bond length changes and charge transfer
reveal the physical mechanism of high-temperature superconductivity, where the
H atom continuously gains electrons leading to the transition of H+ ions to
atomic H, facilitating metallization of hydrogen under mild pressure. Our
results also reveal two strong linear scalar relationships, one is the H-atom
charge versus superconducting transition temperature and the other is the first
ionization energy versus the highest superconducting transition temperature.
Besides, ZnN2H8, CdN2H8, and HgN2H8 were found to be superconductors at ambient
pressure, and the presence of interstitial electrons suggests that they are
also electrides, whose relatively low work functions (3.03, 2.78, and 3.05 eV)
imply that they can be used as catalysts for nitrogen reduction reactions as
well.
|
[{'version': 'v1', 'created': 'Mon, 20 Jun 2022 15:28:20 GMT'}
{'version': 'v2', 'created': 'Tue, 5 Jul 2022 17:40:42 GMT'}]
|
2022-11-23
|
[array(['Wan', 'Zhongyu', ''], dtype=object)
array(['Zhang', 'Ruiqin', ''], dtype=object)]
|
18,423 |
1603.01271
|
Sarthak Dasadia
|
Sarthak Dasadia, Ming Sun, Craig Sarazin, Andrea Morandi, Maxim
Markevitch, Daniel Wik, Luigina Feretti, Gabriele Giovannini, Federica
Govoni, Valentina Vacca
|
A Strong Merger Shock in Abell 665
|
Accepted for publication in ApJL
| null |
10.3847/2041-8205/820/1/L20
| null |
astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Deep (103 ks) \chandra\ observations of Abell 665 have revealed rich
structures in this merging galaxy cluster, including a strong shock and two
cold fronts. The newly discovered shock has a Mach number of $M$ = 3.0 $\pm$
0.6, propagating in front of a cold disrupted cloud. This makes Abell~665 the
second cluster where a strong merger shock of $M \approx$ 3 has been detected,
after the Bullet cluster. The shock velocity from jump conditions is consistent
with (2.7 $\pm$ 0.7) $\times$ 10$^3$ km sec$^{-1}$. The new data also reveal a
prominent southern cold front, with potentially heated gas ahead of it. Abell
665 also hosts a giant radio halo. There is a hint of diffuse radio emission
extending to the shock at the north, which needs to be examined with better
radio data. This new strong shock provides a great opportunity to study the
re-acceleration model with the X-ray and radio data combined.
|
[{'version': 'v1', 'created': 'Thu, 3 Mar 2016 21:00:03 GMT'}]
|
2016-03-23
|
[array(['Dasadia', 'Sarthak', ''], dtype=object)
array(['Sun', 'Ming', ''], dtype=object)
array(['Sarazin', 'Craig', ''], dtype=object)
array(['Morandi', 'Andrea', ''], dtype=object)
array(['Markevitch', 'Maxim', ''], dtype=object)
array(['Wik', 'Daniel', ''], dtype=object)
array(['Feretti', 'Luigina', ''], dtype=object)
array(['Giovannini', 'Gabriele', ''], dtype=object)
array(['Govoni', 'Federica', ''], dtype=object)
array(['Vacca', 'Valentina', ''], dtype=object)]
|
18,424 |
2201.06561
|
Mikio Sakurai
|
Mikio Sakurai, Andreas Adelmann, Malte Backhaus, Niklaus Berger,
Manfred Daum, Kim Siang Khaw, Klaus Kirch, Andreas Knecht, Angela Papa,
Claude Petitjean, Philipp Schmidt-Wellenburg
|
muEDM: Towards a search for the muon electric dipole moment at PSI using
the frozen-spin technique
|
5 pages, 3 figures, prepared for the conference proceedings of the
24th International Spin Symposium (SPIN2021) in Matsue, Japan. Minor
modifications to match accepted version
| null |
10.7566/JPSCP.37.020604
| null |
hep-ex physics.ins-det
|
http://creativecommons.org/licenses/by-nc-sa/4.0/
|
The search for a permanent electric dipole moment (EDM) of the muon is an
excellent probe for physics beyond the Standard Model of particle physics. We
propose the first dedicated muon EDM search employing the frozen-spin technique
at the Paul Scherrer Institute (PSI), Switzerland, with a sensitivity of $6
\times 10^{-23}~e\!\cdot\!\mathrm{cm}$, improving the current best limit set by
the E821 experiment at Brookhaven National Laboratory by more than three orders
of magnitude. In preparation for a high precision experiment to measure the
muon EDM, several R&D studies have been performed at PSI: the characterisation
of a possible beamline to host the experiment for the muon beam injection study
and the measurement of the multiple Coulomb scattering of positrons in
potential detector materials at low momenta for the positron tracking scheme
development. This paper discusses experimental concepts and the current status
of the muEDM experiment at PSI.
|
[{'version': 'v1', 'created': 'Mon, 17 Jan 2022 18:28:24 GMT'}
{'version': 'v2', 'created': 'Mon, 31 Jan 2022 07:56:38 GMT'}]
|
2023-01-18
|
[array(['Sakurai', 'Mikio', ''], dtype=object)
array(['Adelmann', 'Andreas', ''], dtype=object)
array(['Backhaus', 'Malte', ''], dtype=object)
array(['Berger', 'Niklaus', ''], dtype=object)
array(['Daum', 'Manfred', ''], dtype=object)
array(['Khaw', 'Kim Siang', ''], dtype=object)
array(['Kirch', 'Klaus', ''], dtype=object)
array(['Knecht', 'Andreas', ''], dtype=object)
array(['Papa', 'Angela', ''], dtype=object)
array(['Petitjean', 'Claude', ''], dtype=object)
array(['Schmidt-Wellenburg', 'Philipp', ''], dtype=object)]
|
18,425 |
1311.0828
|
Nicholas Malaya Mr.
|
Todd A. Oliver, Nicholas Malaya, Rhys Ulerich, Robert D. Moser
|
Estimating Uncertainties in Statistics Computed from DNS
|
42 Pages, 17 Figures, Submitted to Physics of Fluids
| null |
10.1063/1.4866813
| null |
physics.flu-dyn nlin.CD physics.comp-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Rigorous assessment of uncertainty is crucial to the utility of DNS results.
Uncertainties in the computed statistics arise from two sources: finite
statistical sampling and the discretization of the Navier-Stokes equations. Due
to the presence of non-trivial sampling error, standard techniques for
estimating discretization error (such as Richardson extrapolation) fail or are
unreliable. This work provides a systematic and unified approach for estimating
these errors. First, a sampling error estimator that accounts for correlation
in the input data is developed. Then, this sampling error estimate is used as
part of a Bayesian extension of Richardson extrapolation in order to
characterize the discretization error. These methods are tested using the
Lorenz equations and are shown to perform well. These techniques are then used
to investigate the sampling and discretization errors in the DNS of a
wall-bounded turbulent flow. For both cases, it is found that while the
sampling uncertainty is large enough to make the order of accuracy difficult to
determine, the estimated discretization errors are quite small. This indicates
that the commonly used heuristics provide ad- equate resolution for this class
of problems. However, it is also found that, for some quantities, the
discretization error is not small relative to sampling error, indicating that
the conventional wisdom that sampling error dominates discretization error for
this class of simulations needs to be reevaluated.
|
[{'version': 'v1', 'created': 'Mon, 4 Nov 2013 19:59:20 GMT'}]
|
2015-06-17
|
[array(['Oliver', 'Todd A.', ''], dtype=object)
array(['Malaya', 'Nicholas', ''], dtype=object)
array(['Ulerich', 'Rhys', ''], dtype=object)
array(['Moser', 'Robert D.', ''], dtype=object)]
|
18,426 |
1204.0376
|
Santosh Shelly Sharma
|
S. Shelly Sharma and N. K. Sharma
|
Classification of Multipartite Entanglement via Negativity Fonts
|
5 pages, No figures, Corrected typos
|
Phys. Rev. A 85, 042315 (2012)
|
10.1103/PhysRevA.85.042315
| null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Partial transposition of state operator is a well known tool to detect
quantum correlations between two parts of a composite system. In this letter,
the global partial transpose (GPT) is linked to conceptually multipartite
underlying structures in a state - the negativity fonts. If K-way negativity
fonts with non zero determinants exist, then selective partial transposition of
a pure state, involving K of the N qubits (K leq N) yields an operator with
negative eigevalues, identifying K-body correlations in the state. Expansion of
GPT interms of K-way partially transposed (KPT) operators reveals the nature of
intricate intrinsic correlations in the state. Classification criteria for
multipartite entangled states, based on underlying structure of global partial
transpose of canonical state, are proposed. Number of N-partite entanglement
types for an N qubit system is found to be 2^{N-1}-N+2, while the number of
major entanglement classes is 2^{N-1}-1. Major classes for three and four qubit
states are listed. Subclasses are determined by the number and type of
negativity fonts in canonical state.
|
[{'version': 'v1', 'created': 'Mon, 2 Apr 2012 11:40:49 GMT'}
{'version': 'v2', 'created': 'Wed, 11 Apr 2012 17:41:30 GMT'}]
|
2012-04-17
|
[array(['Sharma', 'S. Shelly', ''], dtype=object)
array(['Sharma', 'N. K.', ''], dtype=object)]
|
18,427 |
1603.00354
|
Jamel Ben Amara
|
Jamel Ben Amara and Hedhly Jihed
|
The Ratio of Eigenvalues of the Dirichlet Eigenvalue Problem for
Equations with One-Dimensional p-Laplacian
|
5 pages, 0 figures
| null | null | null |
math.SP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Chao-Zhong Chen et al. $[{Proc}.$ ${Amer. Math. Soc},2013],$ proved the upper
estimate
$\frac{\lambda _{n}}{\lambda _{m}}\leq \frac{% n^{p}}{m^{p}}$ $ (n>m\geq 1) $
for Dirichlet Shr\"{o}dinger operators with nonnegative and single-well
potentials. In this paper we discuss the case of nonpositive potentials $q(x)$
continuous on the interval $[ 0,1] $. We prove that if $q(x)\leq 0$ and
single-barrier then $\frac{\lambda _{n}}{\lambda _{m}}\geq \frac{n^{p}%
}{m^{p}}$ for $\lambda _{n}>\lambda _{m}\geq -2q^{\ast },$ where
$q^{\ast}=\inf\{q(0), q(1)\}$. Furthermore, we show that there exists
$\ell_{0}\in ( 0,1] $ such that for all $\ell\in(0,\ell_{0}],$ the associated
eigenvalues $(\lambda _{n}(\ell)) _{n\geq 1}$ (of the problem defined on
$[0,\ell]$) satisfy $ \lambda _{1}( \ell)>0$ and $\frac{\lambda _{n}(
\ell)}{\lambda _{m}( \ell) }\geq \frac{n^{p}}{m^{p}}$ $n>m\geq 1$. The value
$\ell _{0}$ satisfies the following estimate $0<\ell_{0}\leq
\sqrt[p]{\frac{-p}{3q^{*}}}$.
|
[{'version': 'v1', 'created': 'Tue, 1 Mar 2016 16:50:31 GMT'}]
|
2016-03-02
|
[array(['Amara', 'Jamel Ben', ''], dtype=object)
array(['Jihed', 'Hedhly', ''], dtype=object)]
|
18,428 |
2202.02832
|
Peter Bevan
|
Peter J. Bevan and Amir Atapour-Abarghouei
|
Detecting Melanoma Fairly: Skin Tone Detection and Debiasing for Skin
Lesion Classification
|
8 pages
| null | null | null |
eess.IV cs.CV
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Convolutional Neural Networks have demonstrated human-level performance in
the classification of melanoma and other skin lesions, but evident performance
disparities between differing skin tones should be addressed before widespread
deployment. In this work, we propose an efficient yet effective algorithm for
automatically labelling the skin tone of lesion images, and use this to
annotate the benchmark ISIC dataset. We subsequently use these automated labels
as the target for two leading bias unlearning techniques towards mitigating
skin tone bias. Our experimental results provide evidence that our skin tone
detection algorithm outperforms existing solutions and that unlearning skin
tone may improve generalisation and can reduce the performance disparity
between melanoma detection in lighter and darker skin tones.
|
[{'version': 'v1', 'created': 'Sun, 6 Feb 2022 18:53:06 GMT'}
{'version': 'v2', 'created': 'Tue, 8 Feb 2022 20:42:06 GMT'}
{'version': 'v3', 'created': 'Thu, 30 Jun 2022 10:27:59 GMT'}
{'version': 'v4', 'created': 'Fri, 29 Jul 2022 08:20:11 GMT'}]
|
2022-08-01
|
[array(['Bevan', 'Peter J.', ''], dtype=object)
array(['Atapour-Abarghouei', 'Amir', ''], dtype=object)]
|
18,429 |
1405.3156
|
Markus Weimar
|
Dirk Nuyens and Gowri Suryanarayana and Markus Weimar
|
Rank-1 lattice rules for multivariate integration in spaces of
permutation-invariant functions: Error bounds and tractability
|
26 pages; minor changes due to reviewer's comments; the final
publication is available at link.springer.com
| null |
10.1007/s10444-015-9411-6
| null |
math.NA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study multivariate integration of functions that are invariant under
permutations (of subsets) of their arguments. We find an upper bound for the
$n$th minimal worst case error and show that under certain conditions, it can
be bounded independent of the number of dimensions. In particular, we study the
application of unshifted and randomly shifted rank-$1$ lattice rules in such a
problem setting. We derive conditions under which multivariate integration is
polynomially or strongly polynomially tractable with the Monte Carlo rate of
convergence $O(n^{-1/2})$. Furthermore, we prove that those tractability
results can be achieved with shifted lattice rules and that the shifts are
indeed necessary. Finally, we show the existence of rank-$1$ lattice rules
whose worst case error on the permutation- and shift-invariant spaces converge
with (almost) optimal rate. That is, we derive error bounds of the form
$O(n^{-\lambda/2})$ for all $1 \leq \lambda < 2 \alpha$, where $\alpha$ denotes
the smoothness of the spaces.
Keywords: Numerical integration, Quadrature, Cubature, Quasi-Monte Carlo
methods, Rank-1 lattice rules.
|
[{'version': 'v1', 'created': 'Tue, 13 May 2014 14:04:37 GMT'}
{'version': 'v2', 'created': 'Fri, 6 Mar 2015 22:08:24 GMT'}]
|
2015-03-10
|
[array(['Nuyens', 'Dirk', ''], dtype=object)
array(['Suryanarayana', 'Gowri', ''], dtype=object)
array(['Weimar', 'Markus', ''], dtype=object)]
|
18,430 |
hep-th/0308024
|
Tamiaki Yoneya
|
Masako Asano, Yasuhiro Sekino, and Tamiaki Yoneya
|
PP-Wave Holography for Dp-Brane Backgrounds
|
43 pages, corrected typos, version to be published in Nucl. Phys. B
|
Nucl.Phys. B678 (2004) 197-232
|
10.1016/j.nuclphysb.2003.11.005
|
UT-KOMABA/03-16, KEK-TH-905
|
hep-th
| null |
As an extension of the so-called BMN conjecture, we investigate the
plane-wave limit for possible holographic connection between bulk string
theories in non-conformal backgrounds of D$p$-branes and the corresponding
supersymmetric gauge theories for $p<5$. Our work is based on the tunneling
picture for dominant null trajectories of strings in the limit of large angular
momentum. The tunneling null trajectories start from the near-horizon boundary
and return to the boundary, and the resulting backgrounds are time-dependent
for general D$p$-branes except for $p=3$. We develop a general method for
extracting diagonalized two-point functions for boundary theories as Euclidean
(bulk) S-matrix in the time-dependent backgrounds. For the case of D0-brane,
two-point functions of supergravity modes are shown to agree with the results
derived previously by the perturbative analysis of supergravity. We then
discuss the implications of the holography for general cases of D$p$-branes
including the stringy excitations. All the cases ($p\ne 3, p<5$) exhibit
interesting infra-red behaviors, which are different from free-field theories,
suggesting the existence of quite nontrivial fixed-points in dual gauge
theories.
|
[{'version': 'v1', 'created': 'Mon, 4 Aug 2003 14:37:39 GMT'}
{'version': 'v2', 'created': 'Tue, 5 Aug 2003 07:13:51 GMT'}
{'version': 'v3', 'created': 'Sat, 29 Nov 2003 01:39:04 GMT'}]
|
2010-04-05
|
[array(['Asano', 'Masako', ''], dtype=object)
array(['Sekino', 'Yasuhiro', ''], dtype=object)
array(['Yoneya', 'Tamiaki', ''], dtype=object)]
|
18,431 |
2003.10303
|
David Conal Higgins
|
David Higgins and Vince I. Madai
|
From Bit To Bedside: A Practical Framework For Artificial Intelligence
Product Development In Healthcare
|
30 pages, 4 figures
|
Advanced Intelligent Systems, 2020, 52
|
10.1002/aisy.202000052
| null |
cs.CY cs.AI cs.HC stat.AP stat.ML
|
http://creativecommons.org/licenses/by-sa/4.0/
|
Artificial Intelligence (AI) in healthcare holds great potential to expand
access to high-quality medical care, whilst reducing overall systemic costs.
Despite hitting the headlines regularly and many publications of
proofs-of-concept, certified products are failing to breakthrough to the
clinic. AI in healthcare is a multi-party process with deep knowledge required
in multiple individual domains. The lack of understanding of the specific
challenges in the domain is, therefore, the major contributor to the failure to
deliver on the big promises. Thus, we present a decision perspective framework,
for the development of AI-driven biomedical products, from conception to market
launch. Our framework highlights the risks, objectives and key results which
are typically required to proceed through a three-phase process to the market
launch of a validated medical AI product. We focus on issues related to
Clinical validation, Regulatory affairs, Data strategy and Algorithmic
development. The development process we propose for AI in healthcare software
strongly diverges from modern consumer software development processes. We
highlight the key time points to guide founders, investors and key stakeholders
throughout their relevant part of the process. Our framework should be seen as
a template for innovation frameworks, which can be used to coordinate team
communications and responsibilities towards a reasonable product development
roadmap, thus unlocking the potential of AI in medicine.
|
[{'version': 'v1', 'created': 'Mon, 23 Mar 2020 14:42:18 GMT'}]
|
2021-08-06
|
[array(['Higgins', 'David', ''], dtype=object)
array(['Madai', 'Vince I.', ''], dtype=object)]
|
18,432 |
hep-ph/0511025
|
Dani\"el Boer
|
Daniel Boer
|
Anomalous Drell-Yan asymmetry from hadronic or QCD vacuum effects
|
8 pages, 4 eps figures; Talk presented at the International Workshop
on Transverse Polarization Phenomena in Hard Processes (Transversity 2005),
Villa Olmo, Como, Italy, September 7-10, 2005
| null |
10.1142/9789812773272_0029
| null |
hep-ph
| null |
The anomalously large cos(2 phi) asymmetry measured in the Drell-Yan process
is discussed. Possible origins of this large deviation from the Lam-Tung
relation are considered with emphasis on the comparison of two particular
proposals: one that suggests it arises from a QCD vacuum effect and one that
suggests it is a hadronic effect. Experimental signatures distinguishing these
effects are discussed.
|
[{'version': 'v1', 'created': 'Thu, 3 Nov 2005 11:10:12 GMT'}]
|
2017-08-23
|
[array(['Boer', 'Daniel', ''], dtype=object)]
|
18,433 |
2306.11211
|
Haimei Huo
|
Haimei Huo, Risheng Liu, Zhixun Su
|
A New Simple Stochastic Gradient Descent Type Algorithm With Lower
Computational Complexity for Bilevel Optimization
|
submitted to TNNLS; in the second round of review
| null | null | null |
math.OC
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Bilevel optimization has been widely used in many machine learning
applications such as hyperparameter optimization and meta learning. Recently,
many simple stochastic gradient descent(SGD) type algorithms(without using
momentum and variance techniques) have been proposed to solve the bilevel
optimization problems. However, all the existing simple SGD type algorithms
estimate the hypergradient via stochastic estimation of Neumann series. In the
paper, we propose to estimate the hypergradient via SGD-based Estimation(i.e.,
solving the linear system with SGD). By using warm start initialization
strategy, a new simple SGD type algorithm SSGD based on SGD-based Estimation is
proposed. We provide the convergence rate guarantee for SSGD and show that SSGD
outperforms the best known computational complexity achieved by the existing
simple SGD type algorithms. Our experiments validate our theoretical results
and demonstrate the efficiency of our proposed algorithm SSGD in hyperparameter
optimization applications.
|
[{'version': 'v1', 'created': 'Tue, 20 Jun 2023 00:32:13 GMT'}]
|
2023-06-21
|
[array(['Huo', 'Haimei', ''], dtype=object)
array(['Liu', 'Risheng', ''], dtype=object)
array(['Su', 'Zhixun', ''], dtype=object)]
|
18,434 |
2306.08833
|
Chaofan Wang
|
Chaofan Wang, Samuel Kernan Freire, Mo Zhang, Jing Wei, Jorge
Goncalves, Vassilis Kostakos, Zhanna Sarsenbayeva, Christina Schneegass,
Alessandro Bozzon, Evangelos Niforatos
|
Safeguarding Crowdsourcing Surveys from ChatGPT with Prompt Injection
| null | null | null | null |
cs.HC
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
ChatGPT and other large language models (LLMs) have proven useful in
crowdsourcing tasks, where they can effectively annotate machine learning
training data. However, this means that they also have the potential for
misuse, specifically to automatically answer surveys. LLMs can potentially
circumvent quality assurance measures, thereby threatening the integrity of
methodologies that rely on crowdsourcing surveys. In this paper, we propose a
mechanism to detect LLM-generated responses to surveys. The mechanism uses
"prompt injection", such as directions that can mislead LLMs into giving
predictable responses. We evaluate our technique against a range of question
scenarios, types, and positions, and find that it can reliably detect
LLM-generated responses with more than 93% effectiveness. We also provide an
open-source software to help survey designers use our technique to detect LLM
responses. Our work is a step in ensuring that survey methodologies remain
rigorous vis-a-vis LLMs.
|
[{'version': 'v1', 'created': 'Thu, 15 Jun 2023 03:30:13 GMT'}]
|
2023-06-16
|
[array(['Wang', 'Chaofan', ''], dtype=object)
array(['Freire', 'Samuel Kernan', ''], dtype=object)
array(['Zhang', 'Mo', ''], dtype=object)
array(['Wei', 'Jing', ''], dtype=object)
array(['Goncalves', 'Jorge', ''], dtype=object)
array(['Kostakos', 'Vassilis', ''], dtype=object)
array(['Sarsenbayeva', 'Zhanna', ''], dtype=object)
array(['Schneegass', 'Christina', ''], dtype=object)
array(['Bozzon', 'Alessandro', ''], dtype=object)
array(['Niforatos', 'Evangelos', ''], dtype=object)]
|
18,435 |
2107.03839
|
Rafael Robson Lino dos Santos
|
Gustavo P. de Brito, Astrid Eichhorn, Rafael Robson Lino dos Santos
|
The weak-gravity bound and the need for spin in asymptotically safe
matter-gravity models
|
18 pages + appendix, 18 figures. Version identical with published
one, except for correction of typo in Eq. 3.6
| null |
10.1007/JHEP11(2021)110
| null |
gr-qc hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discover a weak-gravity bound in scalar-gravity systems in the
asymptotic-safety paradigm. The weak-gravity bound arises in these systems
under the approximations we make, when gravitational fluctuations exceed a
critical strength. Beyond this critical strength, gravitational fluctuations
can generate complex fixed-point values in higher-order scalar interactions.
Asymptotic safety can thus only be realized at sufficiently weak gravitational
interactions. We find that within truncations of the matter-gravity dynamics,
the fixed point lies beyond the critical strength, unless spinning matter,
i.e., fermions and vectors, is also included in the model.
|
[{'version': 'v1', 'created': 'Thu, 8 Jul 2021 13:34:29 GMT'}
{'version': 'v2', 'created': 'Tue, 11 Jan 2022 17:48:46 GMT'}]
|
2022-01-12
|
[array(['de Brito', 'Gustavo P.', ''], dtype=object)
array(['Eichhorn', 'Astrid', ''], dtype=object)
array(['Santos', 'Rafael Robson Lino dos', ''], dtype=object)]
|
18,436 |
1411.7866
|
Francesco Dalla Piazza
|
F. Belgiorno, S.L. Cacciatori, F. Dalla Piazza
|
The Hopfield model revisited: Covariance and Quantization
|
14 pages, improvements added
| null | null | null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
There are several possible applications of quantum electrodynamics in
dielectric media which require a quantum description for the electromagnetic
field interacting with matter fields. The associated quantum models can refer
to macroscopic electromagnetic fields or, in alternative, to mesoscopic fields
(polarization fields) describing an effective interaction between
electromagnetic field and matter fields. We adopt the latter approach, and
focus on the Hopfield model for the electromagnetic field in a dielectric
dispersive medium in a framework in which space-time dependent mesoscopic
parameters occur, like susceptibility, matter resonance frequency, and also
coupling between electromagnetic field and polarization field. Our most direct
goal is to describe in a phenomenological way a space-time varying dielectric
perturbation induced by means of the Kerr effect in nonlinear dielectric media.
This extension of the model is implemented by means of a Lorentz-invariant
Lagrangian which, for constant microscopic parameters, and in the rest frame,
coincides with the standard one. Moreover, we deduce a covariant scalar product
and provide a covariant quantization scheme which keeps into account the
constraints implicit in the model. Examples of viable applications are
indicated.
|
[{'version': 'v1', 'created': 'Fri, 28 Nov 2014 13:45:13 GMT'}
{'version': 'v2', 'created': 'Thu, 7 Jan 2016 10:56:05 GMT'}]
|
2016-01-08
|
[array(['Belgiorno', 'F.', ''], dtype=object)
array(['Cacciatori', 'S. L.', ''], dtype=object)
array(['Piazza', 'F. Dalla', ''], dtype=object)]
|
18,437 |
2002.02915
|
Alexander Nagel
|
Alexander Nagel and Malabika Pramanik
|
Bergman spaces under maps of monomial type
|
26 pages; Added references
| null | null | null |
math.CV
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
For appropriate domains $\Omega_{1}, \Omega_{2}$ we consider mappings
$\Phi_{\mathbf A}:\Omega_{1}\to\Omega_{2}$ of monomial type. We obtain an
orthogonal decomposition of the Bergman space $\mathcal A^{2}(\Omega_{1})$ into
finitely many closed subspaces indexed by characters of a finite Abelian group
associated to the mapping $\Phi_{\mathbf A}$. We then show that each subspace
is isomorphic to a weighted Bergman space on $\Omega_{2}$. This leads to a
formula for the Bergman kernel on $\Omega_{1}$ as a sum of weighted Bergman
kernels on $\Omega_{2}$
|
[{'version': 'v1', 'created': 'Fri, 7 Feb 2020 17:30:37 GMT'}
{'version': 'v2', 'created': 'Wed, 8 Apr 2020 17:57:12 GMT'}]
|
2020-04-09
|
[array(['Nagel', 'Alexander', ''], dtype=object)
array(['Pramanik', 'Malabika', ''], dtype=object)]
|
18,438 |
1010.3453
|
Juan Garcia-Bellido
|
David Alonso, Juan Garcia-Bellido, Troels Haugboelle and Julian
Vicente
|
Large scale structure simulations of inhomogeneous LTB void models
|
7 pages, 6 figures, published in Physical Review D
|
Phys.Rev.D82:123530,2010
|
10.1103/PhysRevD.82.123530
|
IFT-UAM/CSIC-10-54
|
astro-ph.CO gr-qc
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We perform numerical simulations of large scale structure evolution in an
inhomogeneous Lemaitre-Tolman-Bondi (LTB) model of the Universe. We follow the
gravitational collapse of a large underdense region (a void) in an otherwise
flat matter-dominated Einstein-deSitter model. We observe how the (background)
density contrast at the centre of the void grows to be of order one, and show
that the density and velocity profiles follow the exact non-linear LTB solution
to the full Einstein equations for all but the most extreme voids. This result
seems to contradict previous claims that fully relativistic codes are needed to
properly handle the non-linear evolution of large scale structures, and that
local Newtonian dynamics with an explicit expansion term is not adequate. We
also find that the (local) matter density contrast grows with the scale factor
in a way analogous to that of an open universe with a value of the matter
density OmegaM(r) corresponding to the appropriate location within the void.
|
[{'version': 'v1', 'created': 'Sun, 17 Oct 2010 22:14:57 GMT'}
{'version': 'v2', 'created': 'Tue, 11 Jan 2011 09:39:54 GMT'}]
|
2015-03-17
|
[array(['Alonso', 'David', ''], dtype=object)
array(['Garcia-Bellido', 'Juan', ''], dtype=object)
array(['Haugboelle', 'Troels', ''], dtype=object)
array(['Vicente', 'Julian', ''], dtype=object)]
|
18,439 |
1209.5368
|
Andrzej Wi\'snicki
|
Anna Betiuk-Pilarska and Andrzej Wi\'snicki
|
On the Suzuki nonexpansive-type mappings
|
15 pages
|
Ann. Funct. Anal. 4 (2013), 72-86
| null | null |
math.FA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It is shown that if $C$ is a nonempty convex and weakly compact subset of a
Banach space $X$ with $M(X)>1$ and $T:C\rightarrow C$ satisfies condition $(C)$
or is continuous and satisfies condition $(C_{\lambda})$ for some $\lambda \in
(0,1)$, then $T$ has a fixed point. In particular, our theorem holds for
uniformly nonsquare Banach spaces. A similar statement is proved for nearly
uniformly noncreasy spaces.
|
[{'version': 'v1', 'created': 'Mon, 24 Sep 2012 19:08:54 GMT'}]
|
2015-11-24
|
[array(['Betiuk-Pilarska', 'Anna', ''], dtype=object)
array(['Wiśnicki', 'Andrzej', ''], dtype=object)]
|
18,440 |
hep-th/9507089
| null |
E.Vinteler
|
Quantum Chaos in Multi-Matrix Models
|
15 pages, Latex; 1 figure (available from author )
| null | null | null |
hep-th
| null |
We propose a possible resolution for the problem of why the semicircular law
is not observed, whilst the random matrix hypothesis describes well the
fluctuation of energy spectra. We show in the random 2-matrix model that the
interactions between the quantum subsystems alter the semicircular law of level
density. We consider also other types of interactions in the chain- and
star-multimatrix models. The connection with the Calogero-Sutherland models is
briefly discussed.
|
[{'version': 'v1', 'created': 'Mon, 17 Jul 1995 14:05:32 GMT'}]
|
2007-05-23
|
[array(['Vinteler', 'E.', ''], dtype=object)]
|
18,441 |
0712.2074
|
Yasunori Nomura
|
Yasunori Nomura, Michele Papucci, Daniel Stolarski
|
Flavorful Supersymmetry
|
20 pages; typos corrected, comments added, to appear in PRD
|
Phys.Rev.D77:075006,2008
|
10.1103/PhysRevD.77.075006
|
UCB-PTH-07/25
|
hep-ph
| null |
Weak scale supersymmetry provides elegant solutions to many of the problems
of the standard model, but it also generically gives rise to excessive flavor
and CP violation. We show that if the mechanism that suppresses the Yukawa
couplings also suppresses flavor changing interactions in the supersymmetry
breaking parameters, essentially all the low energy flavor and CP constraints
can be satisfied. The standard assumption of flavor universality in the
supersymmetry breaking sector is not necessary. We study signatures of this
framework at the LHC. The mass splitting among different generations of squarks
and sleptons can be much larger than in conventional scenarios, and even the
mass ordering can be changed. We find that there is a plausible scenario in
which the NLSP is a long-lived right-handed selectron or smuon decaying into
the LSP gravitino. This leads to the spectacular signature of monochromatic
electrons or muons in a stopper detector, providing strong evidence for the
framework.
|
[{'version': 'v1', 'created': 'Thu, 13 Dec 2007 20:48:38 GMT'}
{'version': 'v2', 'created': 'Mon, 17 Mar 2008 21:27:21 GMT'}]
|
2008-11-26
|
[array(['Nomura', 'Yasunori', ''], dtype=object)
array(['Papucci', 'Michele', ''], dtype=object)
array(['Stolarski', 'Daniel', ''], dtype=object)]
|
18,442 |
astro-ph/0207416
|
Nicole Homeier
|
N. Homeier (1), R. Blum (2), P. Conti (3), A. Pasquali (4), A.
Damineli (5) ((1) ESO-Garching and UWisconsin-Madison, (2) CTIO, La Serena,
(3) JILA, UColorado-Boulder, (4) ST-ECF/ESO-Garching, (5) IAG, Sao Paulo)
|
A Near-Infrared Survey for Galactic Wolf-Rayet Stars
|
3 pages, to appear in "A Massive Star Odyssey: from Main Sequence to
Supernova", ed. K. A. van der Hucht, Proc. IAU Symp. 212 (San Francisco:
ASP), in prep
| null |
10.1051/0004-6361:20021569
| null |
astro-ph
| null |
Most of the Milky Way's evolved massive stellar population is hidden from
view. We can attempt to remedy this situation with near-infrared observations,
and in this paper we present our method for detecting Wolf-Rayet stars in
highly extincted regions and apply it to the inner Galaxy. Using narrow band
filters at K-band wavelengths, we demonstrate how WR stars can be detected in
regions where they are optically obscured. Candidates are selected for
spectroscopic follow-up from our relative line and continuum photometry. The
final results of applying this method with a NIR survey in the Galactic plane
will provide a more complete knowledge of the structure of the galactic disk,
the role of metallicity in massive stellar evolution, and environments of
massive star formation. In this paper we briefly describe the survey set-up and
report on recent progress. We have discovered four emission-line objects in the
inner Galaxy: two with nebular emission lines, and two new WR stars, both of
late WC subtype.
|
[{'version': 'v1', 'created': 'Fri, 19 Jul 2002 09:16:15 GMT'}]
|
2009-11-07
|
[array(['Homeier', 'N.', ''], dtype=object)
array(['Blum', 'R.', ''], dtype=object)
array(['Conti', 'P.', ''], dtype=object)
array(['Pasquali', 'A.', ''], dtype=object)
array(['Damineli', 'A.', ''], dtype=object)]
|
18,443 |
1302.1552
|
Michael Kearns
|
Michael Kearns, Yishay Mansour, Andrew Y. Ng
|
An Information-Theoretic Analysis of Hard and Soft Assignment Methods
for Clustering
|
Appears in Proceedings of the Thirteenth Conference on Uncertainty in
Artificial Intelligence (UAI1997)
| null | null |
UAI-P-1997-PG-282-293
|
cs.LG stat.ML
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Assignment methods are at the heart of many algorithms for unsupervised
learning and clustering - in particular, the well-known K-means and
Expectation-Maximization (EM) algorithms. In this work, we study several
different methods of assignment, including the "hard" assignments used by
K-means and the ?soft' assignments used by EM. While it is known that K-means
minimizes the distortion on the data and EM maximizes the likelihood, little is
known about the systematic differences of behavior between the two algorithms.
Here we shed light on these differences via an information-theoretic analysis.
The cornerstone of our results is a simple decomposition of the expected
distortion, showing that K-means (and its extension for inferring general
parametric densities from unlabeled sample data) must implicitly manage a
trade-off between how similar the data assigned to each cluster are, and how
the data are balanced among the clusters. How well the data are balanced is
measured by the entropy of the partition defined by the hard assignments. In
addition to letting us predict and verify systematic differences between
K-means and EM on specific examples, the decomposition allows us to give a
rather general argument showing that K ?means will consistently find densities
with less "overlap" than EM. We also study a third natural assignment method
that we call posterior assignment, that is close in spirit to the soft
assignments of EM, but leads to a surprisingly different algorithm.
|
[{'version': 'v1', 'created': 'Wed, 6 Feb 2013 15:57:20 GMT'}]
|
2013-02-08
|
[array(['Kearns', 'Michael', ''], dtype=object)
array(['Mansour', 'Yishay', ''], dtype=object)
array(['Ng', 'Andrew Y.', ''], dtype=object)]
|
18,444 |
2209.07868
|
Lutz Duembgen
|
Lutz Duembgen and Alexandre Moesching
|
On Stochastic Orders and Total Positivity
| null |
ESAIM: Probability and Statistics 2023
|
10.1051/ps/2023005
| null |
math.ST stat.TH
|
http://creativecommons.org/licenses/by/4.0/
|
The usual stochastic order and the likelihood ratio order between probability
distributions on the real line are reviewed in full generality. In addition,
for the distribution of a random pair $(X,Y)$, it is shown that the conditional
distributions of $Y$, given $X = x$, are increasing in $x$ with respect to the
likelihood ratio order if and only if the joint distribution of $(X,Y)$ is
totally positive of order two (TP2) in a certain sense. It is also shown that
these three types of constraints are stable under weak convergence, and that
weak convergence of TP2 distributions implies convergence of the conditional
distributions just mentioned.
|
[{'version': 'v1', 'created': 'Fri, 16 Sep 2022 11:50:49 GMT'}
{'version': 'v2', 'created': 'Tue, 21 Feb 2023 12:39:25 GMT'}
{'version': 'v3', 'created': 'Tue, 7 Mar 2023 10:21:38 GMT'}]
|
2023-03-08
|
[array(['Duembgen', 'Lutz', ''], dtype=object)
array(['Moesching', 'Alexandre', ''], dtype=object)]
|
18,445 |
cond-mat/0408243
|
Christian Buth
|
Christian Buth, Beate Paulus
|
Basis set convergence in extended systems: infinite hydrogen fluoride
and hydrogen chloride chains
|
12 pages, 4 figures, 4 tables, LaTeX, corrected typos
|
Chem. Phys. Lett. 398, 44--49 (2004)
|
10.1016/j.cplett.2004.08.135
| null |
cond-mat.other cond-mat.mtrl-sci
| null |
Basis set convergence of the Hartree-Fock and the correlation energy is
examined for the hydrogen bonded infinite bent chains (HF)_infinity and
(HCl)_infinity. We employ series of correlation consistent basis sets up to
quintuple zeta quality together with a coupled cluster method (CCSD) to
describe electron correlation on ab initio level. The Hartree-Fock energy
converges rapidly with increasing basis set quality whereas the correlation
energy is found to be slowly convergent for the same series of basis sets. We
study basis set extrapolation for (HF)_infinity and (HCl)_infinity and show
that it substantially enhances the accuracy of both the Hartree-Fock and the
correlation energy in extended systems.
|
[{'version': 'v1', 'created': 'Wed, 11 Aug 2004 10:32:54 GMT'}
{'version': 'v2', 'created': 'Mon, 21 Nov 2005 16:26:38 GMT'}]
|
2007-05-23
|
[array(['Buth', 'Christian', ''], dtype=object)
array(['Paulus', 'Beate', ''], dtype=object)]
|
18,446 |
2209.04246
|
Katharina Lenk
|
Katharina Lenk, Jiajun Li, Philipp Werner, Martin Eckstein
|
Dynamical mean-field study of a photon-mediated ferroelectric phase
transition
| null |
Phys. Rev. B 106, 245124 (2022)
|
10.1103/PhysRevB.106.245124
| null |
cond-mat.str-el
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The interplay of light and matter gives rise to intriguing cooperative
effects in quantum many-body systems. This is even true in thermal equilibrium,
where the electromagnetic field can hybridize with collective modes of matter,
and virtual photons can induce interactions in the solid. Here, we show how
these light-mediated interactions can be treated using the dynamical mean-field
theory formalism. We consider a minimal model of a two-dimensional material
that couples to a surface plasmon polariton mode of a metal-dielectric
interface. Within the mean-field approximation, the system exhibits a
ferroelectric phase transition that is unaffected by the light-matter coupling.
Bosonic dynamical mean-field theory provides a more accurate description and
reveals that the photon-mediated interactions enhance the ferroelectric order
and stabilize the ferroelectric phase.
|
[{'version': 'v1', 'created': 'Fri, 9 Sep 2022 11:14:42 GMT'}
{'version': 'v2', 'created': 'Fri, 16 Dec 2022 07:47:55 GMT'}]
|
2022-12-19
|
[array(['Lenk', 'Katharina', ''], dtype=object)
array(['Li', 'Jiajun', ''], dtype=object)
array(['Werner', 'Philipp', ''], dtype=object)
array(['Eckstein', 'Martin', ''], dtype=object)]
|
18,447 |
1806.10718
|
Emmanuel Motheau
|
Matthew Emmett, Emmanuel Motheau, Weiqun Zhang, Michael Minion, John
B. Bell
|
A Fourth-Order Adaptive Mesh Refinement Algorithm for the
Multicomponent, Reacting Compressible Navier-Stokes Equations
| null | null |
10.1080/13647830.2019.1566574
| null |
physics.flu-dyn physics.comp-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper we present a fourth-order in space and time block-structured
adaptive mesh refinement algorithm for the compressible multicomponent reacting
Navier-Stokes equations. The algorithm uses a finite volume approach that
incorporates a fourth-order discretization of the convective terms. The time
stepping algorithm is based on a multi-level spectral deferred corrections
method that enables explicit treatment of advection and diffusion coupled with
an implicit treatment of reactions. The temporal scheme is embedded in a
block-structured adaptive mesh refinement algorithm that includes subcycling in
time with spectral deferred correction sweeps applied on levels. Here we
present the details of the multi-level scheme paying particular attention to
the treatment of coarse-fine boundaries required to maintain fourth-order
accuracy in time. We then demonstrate the convergence properties of the
algorithm on several test cases including both nonreacting and reacting flows.
Finally we present simulations of a vitiated dimethyl ether jet in 2D and a
turbulent hydrogen jet in 3D, both with detailed kinetics and transport.
|
[{'version': 'v1', 'created': 'Thu, 28 Jun 2018 00:06:02 GMT'}
{'version': 'v2', 'created': 'Thu, 3 Jan 2019 01:43:33 GMT'}]
|
2019-02-15
|
[array(['Emmett', 'Matthew', ''], dtype=object)
array(['Motheau', 'Emmanuel', ''], dtype=object)
array(['Zhang', 'Weiqun', ''], dtype=object)
array(['Minion', 'Michael', ''], dtype=object)
array(['Bell', 'John B.', ''], dtype=object)]
|
18,448 |
1409.3828
|
Carl Bender
|
Carl M. Bender and Mariagiovanna Gianfreda
|
PT-symmetric interpretation of the electromagnetic self-force
|
4 pages, 2 figures
| null |
10.1088/1751-8113/48/34/34FT01
| null |
hep-th math-ph math.MP quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In 1980 Englert examined the classic problem of the electromagnetic
self-force on an oscillating charged particle. His approach, which was based on
an earlier idea of Bateman, was to introduce a charge-conjugate particle and to
show that the two-particle system is Hamiltonian. Unfortunately, Englert's
model did not solve the problem of runaway modes, and the corresponding quantum
theory had ghost states. It is shown here that Englert's Hamiltonian is PT
symmetric, and that the problems with his model arise because the PT symmetry
is broken at both the classical and quantum level. However, by allowing the
charged particles to interact and by adjusting the coupling parameters to put
the model into an unbroken PT-symmetric region, one eliminates the classical
runaway modes and obtains a corresponding quantum system that is ghost free.
|
[{'version': 'v1', 'created': 'Fri, 12 Sep 2014 19:39:51 GMT'}]
|
2015-09-02
|
[array(['Bender', 'Carl M.', ''], dtype=object)
array(['Gianfreda', 'Mariagiovanna', ''], dtype=object)]
|
18,449 |
1708.09582
|
Parasharam Shirage Professor
|
Amit Kumar Rana, Rajasree Das, Yogendra Kumar, Somaditya Sen,
Parasharam M. Shirage
|
Growth of transparent Zn1-xSrxO films by facile wet chemical method:
Effect of Sr doping on the structural, optical and sensing properties
| null |
Applied Surface Science 379, 23-32 (2016)
|
10.1016/j.apsusc.2016.04.066
| null |
cond-mat.mtrl-sci
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Sr doped ZnO nanorods thin films are prepared using wet chemical technique on
transparent flexible substrate. Effect of Sr doping on structural and optical
properties of ZnO is systematically investigated. The sensing property of the
ZnO is enhanced by Sr doping and imitates as a promising material for future
toxic and flammable gas sensor applications as well as for optoelectronic
devices.
|
[{'version': 'v1', 'created': 'Thu, 31 Aug 2017 06:40:16 GMT'}]
|
2017-09-01
|
[array(['Rana', 'Amit Kumar', ''], dtype=object)
array(['Das', 'Rajasree', ''], dtype=object)
array(['Kumar', 'Yogendra', ''], dtype=object)
array(['Sen', 'Somaditya', ''], dtype=object)
array(['Shirage', 'Parasharam M.', ''], dtype=object)]
|
18,450 |
cond-mat/0402045
|
Mika Sillanpaa
|
Mika A. Sillanpaa, Leif Roschier, Pertti J. Hakonen
|
The Inductive Single-Electron Transistor (L-SET)
|
10 pages
|
Phys. Rev. Lett. 93, 066805 (2004)
|
10.1103/PhysRevLett.93.066805
| null |
cond-mat.mes-hall cond-mat.supr-con
| null |
We demonstrate a sensitive method of charge detection based on
radio-frequency readout of the Josephson inductance of a superconducting
single-electron transistor. Charge sensitivity $1.4 \times 10^{-4}e/\sqrt{Hz}$,
limited by preamplifier, is achieved in an operation mode which takes advantage
of the nonlinearity of the Josephson potential. Owing to reactive readout, our
setup has more than two orders of magnitude lower dissipation than the existing
method of radio-frequency electrometry. With an optimized sample, we expect
uncoupled energy sensitivity below $\hbar$ in the same experimental scheme.
|
[{'version': 'v1', 'created': 'Mon, 2 Feb 2004 16:44:18 GMT'}]
|
2009-11-10
|
[array(['Sillanpaa', 'Mika A.', ''], dtype=object)
array(['Roschier', 'Leif', ''], dtype=object)
array(['Hakonen', 'Pertti J.', ''], dtype=object)]
|
18,451 |
0704.3567
|
Gernot Maier
|
Gernot Maier, Johannes Knapp
|
Cosmic-Ray Events as Background in Imaging Atmospheric Cherenkov
Telescopes
|
Accepted by Journal of Astroparticle Physics
|
Astropart.Phys.28:72-81,2007
|
10.1016/j.astropartphys.2007.04.009
| null |
astro-ph
| null |
The dominant background for observations of gamma-rays in the energy region
above 50 GeV with Imaging Atmospheric Cherenkov telescopes are cosmic-ray
events. The images of most of the cosmic ray showers look significantly
different from those of gamma-rays and are therefore easily discriminated.
However, a small fraction of events seems to be indistinguishable from
gamma-rays. This constitutes an irreducible background to the observation of
high-energy gamma-ray sources, and limits the sensitivity achievable with a
given instrument. Here, a Monte Carlo study of gamma-like cosmic-ray events is
presented. The nature of gamma-like cosmic-ray events, the shower particles
that are responsible for the gamma-like appearance, and the dependence of these
results on the choice of the hadronic interaction model are investigated. Most
of the gamma-like cosmic ray events are characterised by the production of
high-energy pi0's early in the shower development which dump most of the shower
energy into electromagnetic sub-showers. Also Cherenkov light from single muons
can mimic gamma-rays in close-by pairs of telescopes. Differences of up to 25%
in the collection area for gamma-like proton showers between QGSJet/FLUKA and
Sibyll/FLUKA simulations have been found.
|
[{'version': 'v1', 'created': 'Thu, 26 Apr 2007 15:10:46 GMT'}]
|
2009-06-23
|
[array(['Maier', 'Gernot', ''], dtype=object)
array(['Knapp', 'Johannes', ''], dtype=object)]
|
18,452 |
2303.10576
|
Zuoyu Yan
|
Zuoyu Yan, Junru Zhou, Liangcai Gao, Zhi Tang, Muhan Zhang
|
Efficiently Counting Substructures by Subgraph GNNs without Running GNN
on Subgraphs
| null | null | null | null |
cs.LG
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using graph neural networks (GNNs) to approximate specific functions such as
counting graph substructures is a recent trend in graph learning. Among these
works, a popular way is to use subgraph GNNs, which decompose the input graph
into a collection of subgraphs and enhance the representation of the graph by
applying GNN to individual subgraphs. Although subgraph GNNs are able to count
complicated substructures, they suffer from high computational and memory
costs. In this paper, we address a non-trivial question: can we count
substructures efficiently with GNNs? To answer the question, we first
theoretically show that the distance to the rooted nodes within subgraphs is
key to boosting the counting power of subgraph GNNs. We then encode such
information into structural embeddings, and precompute the embeddings to avoid
extracting information over all subgraphs via GNNs repeatedly. Experiments on
various benchmarks show that the proposed model can preserve the counting power
of subgraph GNNs while running orders of magnitude faster.
|
[{'version': 'v1', 'created': 'Sun, 19 Mar 2023 05:35:59 GMT'}]
|
2023-03-21
|
[array(['Yan', 'Zuoyu', ''], dtype=object)
array(['Zhou', 'Junru', ''], dtype=object)
array(['Gao', 'Liangcai', ''], dtype=object)
array(['Tang', 'Zhi', ''], dtype=object)
array(['Zhang', 'Muhan', ''], dtype=object)]
|
18,453 |
math/0410346
|
Oliver Lorscheid
|
Oliver Lorscheid
|
Completeness and compactness for varieties over local fields
|
6 pages
| null | null | null |
math.AG
| null |
This paper shows that for K a local field, k a subfield of K and X a variety
over k, X is complete if and only if for every finite field extension K' of K,
X(K') is compact in its strong topology.
|
[{'version': 'v1', 'created': 'Fri, 15 Oct 2004 08:46:27 GMT'}
{'version': 'v2', 'created': 'Wed, 16 Aug 2006 11:23:44 GMT'}]
|
2007-05-23
|
[array(['Lorscheid', 'Oliver', ''], dtype=object)]
|
18,454 |
0912.1707
|
Pawe{\l} Machnikowski
|
Piotr Kaczmarkiewicz, Pawe{\l} Machnikowski
|
Two-phonon polaron resonances in self-assembled quantum dots
|
11 pages
|
Phys. Rev. B 81, 115317 (2010)
|
10.1103/PhysRevB.81.115317
| null |
cond-mat.mes-hall
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the second-order polaronic resonance between 2-LO-phonon states and
p-shell electron states in a quantum dot. We show that the spectrum in the
resonance area can be quantitatively reproduced by a theoretical model using
only standard material constants, without any free parameters. We propose also
a perturbative approach to the problem based on a quasi-degenerate perturbation
theory. This method not only considerably reduces the numerical complexity
without considerable loss of accuracy but also gives some insight into the
structure and origin of the resonance spectrum.
|
[{'version': 'v1', 'created': 'Wed, 9 Dec 2009 10:23:13 GMT'}
{'version': 'v2', 'created': 'Mon, 13 Sep 2010 19:26:48 GMT'}]
|
2010-09-14
|
[array(['Kaczmarkiewicz', 'Piotr', ''], dtype=object)
array(['Machnikowski', 'Paweł', ''], dtype=object)]
|
18,455 |
1310.1545
|
Xuhui Fan
|
Xuhui Fan, Richard Yi Da Xu, Longbing Cao, Yin Song
|
Learning Hidden Structures with Relational Models by Adequately
Involving Rich Information in A Network
| null | null | null | null |
cs.LG cs.SI stat.ML
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Effectively modelling hidden structures in a network is very practical but
theoretically challenging. Existing relational models only involve very limited
information, namely the binary directional link data, embedded in a network to
learn hidden networking structures. There is other rich and meaningful
information (e.g., various attributes of entities and more granular information
than binary elements such as "like" or "dislike") missed, which play a critical
role in forming and understanding relations in a network. In this work, we
propose an informative relational model (InfRM) framework to adequately involve
rich information and its granularity in a network, including metadata
information about each entity and various forms of link data. Firstly, an
effective metadata information incorporation method is employed on the prior
information from relational models MMSB and LFRM. This is to encourage the
entities with similar metadata information to have similar hidden structures.
Secondly, we propose various solutions to cater for alternative forms of link
data. Substantial efforts have been made towards modelling appropriateness and
efficiency, for example, using conjugate priors. We evaluate our framework and
its inference algorithms in different datasets, which shows the generality and
effectiveness of our models in capturing implicit structures in networks.
|
[{'version': 'v1', 'created': 'Sun, 6 Oct 2013 05:47:50 GMT'}]
|
2013-10-08
|
[array(['Fan', 'Xuhui', ''], dtype=object)
array(['Da Xu', 'Richard Yi', ''], dtype=object)
array(['Cao', 'Longbing', ''], dtype=object)
array(['Song', 'Yin', ''], dtype=object)]
|
18,456 |
astro-ph/0512427
|
Adam Lidz
|
Adam Lidz (Harvard-CFA), S. Peng Oh (UCSB), Steven R. Furlanetto
(Caltech)
|
Have We Detected Patchy Reionization in Quasar Spectra?
|
Submitted to ApJ Letters
|
Astrophys.J.639:L47-L60,2006
|
10.1086/502678
| null |
astro-ph
| null |
The Lyman-alpha forest at z >~ 5.5 shows strong scatter in the mean
transmission even when smoothed over very large spatial scales, >~ 50 Mpc/h.
This has been interpreted as a signature of strongly fluctuating radiation
fields, or patchy reionization. To test this claim, we calculate the scatter
arising solely from density fluctuations, with a uniform ionizing background,
using analytic arguments and simulations. This scatter alone is comparable to
that observed. It rises steeply with redshift and is of order unity by z ~ 6,
even on ~ 50 Mpc/h scales. This arises because: i) at z ~ 6, transmission
spectra, which are sensitive mainly to rare voids, are highly biased (with a
linear bias factor b >~ 4-5) tracers of underlying density fluctuations, and
ii) projected power from small-scale transverse modes is aliased to long
wavelength line-of-sight modes. Inferring patchy reionization from quasar
spectra is therefore subtle and requires much more detailed modeling.
Similarly, we expect order unity transmission fluctuations in the z ~ 3 HeII
Lyman-alpha forest from density fluctuations alone, on the scales over which
these measurements are typically made.
|
[{'version': 'v1', 'created': 'Fri, 16 Dec 2005 01:45:40 GMT'}]
|
2009-11-13
|
[array(['Lidz', 'Adam', '', 'Harvard-CFA'], dtype=object)
array(['Oh', 'S. Peng', '', 'UCSB'], dtype=object)
array(['Furlanetto', 'Steven R.', '', 'Caltech'], dtype=object)]
|
18,457 |
2209.13589
|
Aamod Khatiwada
|
Aamod Khatiwada, Grace Fan, Roee Shraga, Zixuan Chen, Wolfgang
Gatterbauer, Ren\'ee J. Miller, Mirek Riedewald
|
SANTOS: Relationship-based Semantic Table Union Search
|
15 pages, 10 figures, to appear at SIGMOD 2023
| null | null | null |
cs.DB
|
http://creativecommons.org/licenses/by/4.0/
|
Existing techniques for unionable table search define unionability using
metadata (tables must have the same or similar schemas) or column-based metrics
(for example, the values in a table should be drawn from the same domain). In
this work, we introduce the use of semantic relationships between pairs of
columns in a table to improve the accuracy of union search. Consequently, we
introduce a new notion of unionability that considers relationships between
columns, together with the semantics of columns, in a principled way. To do so,
we present two new methods to discover semantic relationship between pairs of
columns. The first uses an existing knowledge base (KB), the second (which we
call a "synthesized KB") uses knowledge from the data lake itself. We adopt an
existing Table Union Search benchmark and present new (open) benchmarks that
represent small and large real data lakes. We show that our new unionability
search algorithm, called SANTOS, outperforms a state-of-the-art union search
that uses a wide variety of column-based semantics, including word embeddings
and regular expressions. We show empirically that our synthesized KB improves
the accuracy of union search by representing relationship semantics that may
not be contained in an available KB. This result hints at a promising future of
creating a synthesized KBs from data lakes with limited KB coverage and using
them for union search.
|
[{'version': 'v1', 'created': 'Tue, 27 Sep 2022 17:59:41 GMT'}]
|
2022-09-28
|
[array(['Khatiwada', 'Aamod', ''], dtype=object)
array(['Fan', 'Grace', ''], dtype=object)
array(['Shraga', 'Roee', ''], dtype=object)
array(['Chen', 'Zixuan', ''], dtype=object)
array(['Gatterbauer', 'Wolfgang', ''], dtype=object)
array(['Miller', 'Renée J.', ''], dtype=object)
array(['Riedewald', 'Mirek', ''], dtype=object)]
|
18,458 |
1306.4847
|
Jian Huang
|
Jian Huang, Tingni Sun, Zhiliang Ying, Yi Yu, Cun-Hui Zhang
|
Oracle inequalities for the lasso in the Cox model
|
Published in at http://dx.doi.org/10.1214/13-AOS1098 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org)
|
Annals of Statistics 2013, Vol. 41, No. 3, 1142-1165
|
10.1214/13-AOS1098
|
IMS-AOS-AOS1098
|
math.ST stat.TH
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the absolute penalized maximum partial likelihood estimator in
sparse, high-dimensional Cox proportional hazards regression models where the
number of time-dependent covariates can be larger than the sample size. We
establish oracle inequalities based on natural extensions of the compatibility
and cone invertibility factors of the Hessian matrix at the true regression
coefficients. Similar results based on an extension of the restricted
eigenvalue can be also proved by our method. However, the presented oracle
inequalities are sharper since the compatibility and cone invertibility factors
are always greater than the corresponding restricted eigenvalue. In the Cox
regression model, the Hessian matrix is based on time-dependent covariates in
censored risk sets, so that the compatibility and cone invertibility factors,
and the restricted eigenvalue as well, are random variables even when they are
evaluated for the Hessian at the true regression coefficients. Under mild
conditions, we prove that these quantities are bounded from below by positive
constants for time-dependent covariates, including cases where the number of
covariates is of greater order than the sample size. Consequently, the
compatibility and cone invertibility factors can be treated as positive
constants in our oracle inequalities.
|
[{'version': 'v1', 'created': 'Thu, 20 Jun 2013 12:21:50 GMT'}]
|
2013-06-21
|
[array(['Huang', 'Jian', ''], dtype=object)
array(['Sun', 'Tingni', ''], dtype=object)
array(['Ying', 'Zhiliang', ''], dtype=object)
array(['Yu', 'Yi', ''], dtype=object)
array(['Zhang', 'Cun-Hui', ''], dtype=object)]
|
18,459 |
0709.3070
|
Jean-Francois Gonzalez
|
Guillaume Laibe (CRAL), Jean-Fran\c{c}ois Gonzalez (CRAL), Laure
Fouchet (ETHZ), Sarah T. Maddison (SWINBURNE)
|
3D SPH simulations of grain growth in protoplanetary disks
|
6 pages, 4 figures, to appear in the proceedings of "SF2A-2007:
Semaine de l'Astrophysique Francaise", (J. Bouvier, A. Chalabaev, and C.
Charbonnel eds)
|
Dans SF2A-2007: Semaine de l'Astrophysique Francaise - SF2A-2007:
Semaine de l'Astrophysique Francaise, Grenoble : France (2007)
| null | null |
astro-ph
| null |
We present the first results of the treatment of grain growth in our 3D,
two-fluid (gas+dust) SPH code describing protoplanetary disks. We implement a
scheme able to reproduce the variation of grain sizes caused by a variety of
physical processes and test it with the analytical expression of grain growth
given by Stepinski & Valageas (1997) in simulations of a typical T Tauri disk
around a one solar mass star. The results are in agreement with a turbulent
growing process and validate the method. We are now able to simulate the grain
growth process in a protoplanetary disk given by a more realistic physical
description, currently under development. We discuss the implications of the
combined effect of grain growth and dust vertical settling and radial migration
on subsequent planetesimal formation.
|
[{'version': 'v1', 'created': 'Wed, 19 Sep 2007 16:57:10 GMT'}]
|
2007-09-20
|
[array(['Laibe', 'Guillaume', '', 'CRAL'], dtype=object)
array(['Gonzalez', 'Jean-François', '', 'CRAL'], dtype=object)
array(['Fouchet', 'Laure', '', 'ETHZ'], dtype=object)
array(['Maddison', 'Sarah T.', '', 'SWINBURNE'], dtype=object)]
|
18,460 |
1303.3769
|
Allen Flavell
|
Allen Flavell, Michael Machen, Bob Eisenberg, Chun Liu, Xiaofan Li
|
A Conservative Finite Difference Scheme for Poisson-Nernst-Planck
Equations
| null | null | null | null |
math.NA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A macroscopic model to describe the dynamics of ion transport in ion channels
is the Poisson-Nernst-Planck(PNP) equations. In this paper, we develop a
finite-difference method for solving PNP equations, which is second-order
accurate in both space and time. We use the physical parameters specifically
suited toward the modelling of ion channels. We present a simple iterative
scheme to solve the system of nonlinear equations resulting from discretizing
the equations implicitly in time, which is demonstrated to converge in a few
iterations. We place emphasis on ensuring numerical methods to have the same
physical properties that the PNP equations themselves also possess, namely
conservation of total ions and correct rates of energy dissipation. We describe
in detail an approach to derive a finite-difference method that preserves the
total concentration of ions exactly in time. Further, we illustrate that, using
realistic values of the physical parameters, the conservation property is
critical in obtaining correct numerical solutions over long time scales.
|
[{'version': 'v1', 'created': 'Fri, 15 Mar 2013 13:26:09 GMT'}]
|
2013-03-18
|
[array(['Flavell', 'Allen', ''], dtype=object)
array(['Machen', 'Michael', ''], dtype=object)
array(['Eisenberg', 'Bob', ''], dtype=object)
array(['Liu', 'Chun', ''], dtype=object)
array(['Li', 'Xiaofan', ''], dtype=object)]
|
18,461 |
0910.3525
|
Vicente Munoz
|
Vicente Mu\~noz and Ricardo Perez-Marco
|
Ergodic solenoidal homology: density of ergodic solenoids
|
9 pages, 2 figures
|
Australian J. Math. Anal. and Appl. 6 (2009), no. 1, Article 11,
1-8
| null | null |
math.DG math.DS
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A measured solenoid is a laminated space endowed with a tranversal measure
invariant by holonomy, as defined in arXiv:0910.2836. A measured solenoid
immersed in a smooth manifold produces a closed current (known as generalized
Ruelle-Sullivan current). Uniquely ergodic solenoids are those for which there
is a unique (up to scalars) transversal measure. By the results in
arXiv:0910.2913, for any smooth manifold, any real homology class is
represented by a uniquely ergodic solenoid. In this paper, we prove that the
currents associated to uniquely ergodic solenoids are dense in the space of
closed currents, therefore proving the abundance of such objects.
|
[{'version': 'v1', 'created': 'Mon, 19 Oct 2009 11:09:13 GMT'}]
|
2009-10-20
|
[array(['Muñoz', 'Vicente', ''], dtype=object)
array(['Perez-Marco', 'Ricardo', ''], dtype=object)]
|
18,462 |
1910.05402
|
Changha Choi
|
Changha Choi
|
Phases of Two Adjoints QCD$_{3}$ And a Duality Chain
|
43 pages
| null | null | null |
hep-th cond-mat.str-el
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze the 2+1 dimensional gauge theory with two fermions in the real
adjoint representation with non-zero Chern-Simons level. We propose a new
fermion-fermion dualities between strongly-coupled theories and determine the
quantum phase using the structure of a `Duality Chain'. We argue that when
Chern-Simons level is sufficiently small, the theory in general develops a
strongly coupled quantum phase described by an emergent topological field
theory. For special cases, our proposal predicts an interesting dynamical
scenario with spontaneous breaking of partial 1-form or 0-form global symmetry.
It turns out that $SL(2,\mathbb Z)$ transformation and the generalized
level/rank duality are crucial for the unitary group case. We further unveil
the dynamics of the 2+1 dimensional gauge theory with any pair of
adjoint/rank-two fermions or two bifundamental fermions using similar `Duality
Chain'.
|
[{'version': 'v1', 'created': 'Fri, 11 Oct 2019 20:38:05 GMT'}]
|
2019-10-15
|
[array(['Choi', 'Changha', ''], dtype=object)]
|
18,463 |
1607.03086
|
David Criens
|
David Criens
|
A Note on Real-World and Risk-Neutral Dynamics for Heath-Jarrow-Morton
Frameworks
|
The note has been changed in an applied direction
| null | null | null |
math.PR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
As a consequence of the financial crises, risk management became more
important and real-world dynamics of interest-rate models moved into the focus
of interest. Since risk-neutral dynamics are classically important to compute
prices of financial derivatives, it is interesting when real-world dynamics can
be related to risk-neutral dynamics via an equivalent change of measures. In
this article we give deterministic conditions in a general Heath-Jarrow-Morton
framework driven by a Hilbert space valued Brownian motion and a Poisson random
measure. Our conditions are of Lipschitz type and therefore easy to verify.
|
[{'version': 'v1', 'created': 'Mon, 11 Jul 2016 19:31:07 GMT'}
{'version': 'v2', 'created': 'Tue, 25 Jul 2017 13:40:16 GMT'}]
|
2017-07-26
|
[array(['Criens', 'David', ''], dtype=object)]
|
18,464 |
math/0703505
|
Guofang Wei
|
Guofang Wei and Rugang Ye
|
A Neumann Type Maximum Principle for the Laplace Operator on Compact
Riemannian Manifolds
|
In Theorem A, the previous maximum estimate in terms of the
isoperimetric constant is replaced by a maximum estimate in terms of the
volume-normalized isoperimetric constant. The statements of Gallot's estimate
for the isoperimetric constant are corrected
| null | null | null |
math.DG
| null |
In this paper we present a proof of a Neumann type maximum principle for the
Laplace operator on compact Riemannian manifolds. A key p oint is the simple
geometric nature of the constant in the a priori estimate of this maximum
principle. In particular, this maximum principle can be applied to manifolds
with Ricci curvature bounded from below and diameter bounded from above to
yield a maximum estimate without dependence on a positive lower bound for the
volume.
|
[{'version': 'v1', 'created': 'Fri, 16 Mar 2007 22:16:35 GMT'}
{'version': 'v2', 'created': 'Sun, 11 Nov 2007 23:04:22 GMT'}]
|
2007-11-12
|
[array(['Wei', 'Guofang', ''], dtype=object)
array(['Ye', 'Rugang', ''], dtype=object)]
|
18,465 |
0907.2333
|
Masayo Inoue
|
Masayo Inoue, Kunihiko Kaneko
|
Dynamics of Coupled Adaptive Elements : Bursting and Intermittent
Oscillations Generated by Frustration in Networks
|
12 pages, 13 figures
| null |
10.1103/PhysRevE.81.026203
| null |
physics.bio-ph cond-mat.other nlin.AO q-bio.QM
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Adaptation to environmental change is a common property of biological
systems. Cells initially respond to external changes in the environment, but
after some time, they regain their original state. By considering an element
consisting of two variables that show such adaptation dynamics, we studied a
coupled dynamical system containing such elements to examine the diverse
dynamics in the system and classified the behaviors on the basis of the network
structure that determined the interaction among elements. For a system with two
elements, two types of behaviors, perfect adaptation and simple oscillation,
were observed. For a system with three elements, in addition to these two
types, novel types of dynamics, namely, rapid burst-type oscillation and a slow
cycle, were discovered; depending on the initial conditions, these novel types
of dynamics coexisted. These behaviors are a result of the characteristic
dynamics of each element, i.e., fast response and slow adaptation processes.
The behaviors depend on the network structure (in specific, a combination of
positive or negative feedback among elements). Cooperativity among elements due
to a positive feedback loop leads to simple oscillation, whereas frustration
involving alternating positive and negative interactions among elements leads
to the coexistence of rapid bursting oscillation and a slow cycle. These
behaviors are classified on the basis of the frustration indices defined by the
network structure. The period of the slow cycle is much longer than the
original adaptation time scale, while the burst-type oscillation is a continued
response that does not involve any adaptation. We briefly discuss the universal
applicability of our results to a network of a larger number of elements and
their possible relevance to biological systems.
|
[{'version': 'v1', 'created': 'Tue, 14 Jul 2009 11:45:25 GMT'}]
|
2015-05-13
|
[array(['Inoue', 'Masayo', ''], dtype=object)
array(['Kaneko', 'Kunihiko', ''], dtype=object)]
|
18,466 |
hep-th/9909211
|
Cecile Martin
|
C\'ecile Martin
|
Variational approximations for correlation functions in quantum field
theories
|
60 pages, Latex, to be published in Annals of Physics
|
Annals Phys. 278 (1999) 202-264
|
10.1006/aphy.1999.5978
| null |
hep-th
| null |
Applying the time-dependent variational principle of Balian and V\'en\'eroni,
we derive variational approximations for multi-time correlation functions in
$\Phi^4$ field theory. We assume first that the initial state is given and
characterized by a density operator equal to a Gaussian density matrix. Then,
we study the more realistic situation where only a few expectation values are
given at the initial time and we perform an optimization with respect to the
initial state. We calculate explicitly the two-time correlation functions with
two and four field operators at equilibrium in the symmetric phase.
|
[{'version': 'v1', 'created': 'Wed, 29 Sep 1999 13:01:48 GMT'}]
|
2009-10-31
|
[array(['Martin', 'Cécile', ''], dtype=object)]
|
18,467 |
nlin/0606028
|
Fausto Montoya
|
A. Orue, G. Alvarez, G. Pastor, M. Romera, F. Montoya and Shujun Li
|
A New Lorenz System Parameter Determination Method and Applications
|
21 pages, 14 figures, preprint submitted to Chaos Solitons and
Fractals
| null | null | null |
nlin.CD
| null |
This paper describes how to determine the parameter values of the chaotic
Lorenz system from one of its variables waveform. The geometrical properties of
the system are used firstly to reduce the parameter search space. Then, a
synchronization-based approach, with the help of the same geometrical
properties as coincidence criteria, is implemented to determine the parameter
values with the wanted accuracy. The method is not affected by a moderate
amount of noise in the waveform. As way of example of its effectiveness, the
method is applied to figure out directly from the ciphertext the secret keys of
two-channel chaotic cryptosystems using the variable $z$ as a synchronization
signal, based on the ultimate state projective chaos synchronization.
|
[{'version': 'v1', 'created': 'Sun, 11 Jun 2006 11:37:45 GMT'}]
|
2007-05-23
|
[array(['Orue', 'A.', ''], dtype=object)
array(['Alvarez', 'G.', ''], dtype=object)
array(['Pastor', 'G.', ''], dtype=object)
array(['Romera', 'M.', ''], dtype=object)
array(['Montoya', 'F.', ''], dtype=object)
array(['Li', 'Shujun', ''], dtype=object)]
|
18,468 |
2008.12779
|
Hannah Kwak
|
Hannah Kwak, Jongchul Chae, Maria S. Madjarska, Kyuhyoun Cho, Donguk
Song
|
Impulsive wave excitation by rapidly changing granules
|
11 pages, 13 figures, Accepted for publication in A&A
|
A&A 642, A154 (2020)
|
10.1051/0004-6361/202038288
| null |
astro-ph.SR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It is not yet fully understood how magnetohydrodynamic waves in the interior
and atmosphere of the Sun are excited. Traditionally, turbulent convection in
the interior is considered to be the source of wave excitation in the quiet
Sun. Over the last few decades, acoustic events observed in the intergranular
lanes in the photosphere have emerged as a strong candidate for a wave
excitation source. Here we report our observations of wave excitation by a new
type of event: rapidly changing granules. Our observations were carried out
with the Fast Imaging Solar Spectrograph in the H$\alpha$ and Ca II 8542
$\unicode{xC5}$ lines and the TiO 7057 $\unicode{xC5}$ broadband filter imager
of the 1.6 m Goode Solar Telescope at the Big Bear Solar Observatory. We
identify granules in the internetwork region that undergo rapid dynamic changes
such as collapse (event 1), fragmentation (event 2), or submergence (event 3).
In the photospheric images, these granules become significantly darker than
neighboring granules. Following the granules' rapid changes, transient
oscillations are detected in the photospheric and chromospheric layers. In the
case of event 1, the dominant period of the oscillations is close to 4.2 min in
the photosphere and 3.8 min in the chromosphere. Moreover, in the Ca II$-$0.5
$\unicode{xC5}$ raster image, we observe repetitive brightenings in the
location of the rapidly changing granules that are considered the manifestation
of shock waves. Based on our results, we suggest that dynamic changes of
granules can generate upward-propagating acoustic waves in the quiet Sun that
ultimately develop into shocks.
|
[{'version': 'v1', 'created': 'Fri, 28 Aug 2020 17:59:55 GMT'}]
|
2020-10-14
|
[array(['Kwak', 'Hannah', ''], dtype=object)
array(['Chae', 'Jongchul', ''], dtype=object)
array(['Madjarska', 'Maria S.', ''], dtype=object)
array(['Cho', 'Kyuhyoun', ''], dtype=object)
array(['Song', 'Donguk', ''], dtype=object)]
|
18,469 |
1104.2360
|
John Iskra
|
John Iskra
|
The Category of Locales is Rigid
| null | null | null | null |
math.CT
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper we show that the category of frames, and, thus, the cate- gory
of locales is 'rigid'. This means that every endo-equivalence on them is
isomorphic to the identity functor. To reach this result we prove new results
concerning the number of automorphisms between frames and new results
concerning the order preserving properties of endo-equivalences.
|
[{'version': 'v1', 'created': 'Wed, 13 Apr 2011 01:17:23 GMT'}]
|
2011-04-14
|
[array(['Iskra', 'John', ''], dtype=object)]
|
18,470 |
patt-sol/9606006
|
Jose Geraldo Pereira
|
R.A. Kraenkel, M.A. Manna, V. Merle, J.C. Montero and J.G. Pereira
|
Multiple-Time Higher-Order Perturbation Analysis of the Regularized
Long-Wavelength Equation
|
15 pages, RevTex, no figures (to appear in Phys. Rev. E)
| null |
10.1103/PhysRevE.54.2976
|
IFT-P.020/96
|
patt-sol nlin.PS
| null |
By considering the long-wave limit of the regularized long wave (RLW)
equation, we study its multiple-time higher-order evolution equations. As a
first result, the equations of the Korteweg-de Vries hierarchy are shown to
play a crucial role in providing a secularity-free perturbation theory in the
specific case of a solitary-wave solution. Then, as a consequence, we show that
the related perturbative series can be summed and gives exactly the
solitary-wave solution of the RLW equation. Finally, some comments and
considerations are made on the N-soliton solution, as well as on the
limitations of applicability of the multiple scale method in obtaining uniform
perturbative series.
|
[{'version': 'v1', 'created': 'Thu, 27 Jun 1996 21:23:20 GMT'}]
|
2009-10-30
|
[array(['Kraenkel', 'R. A.', ''], dtype=object)
array(['Manna', 'M. A.', ''], dtype=object)
array(['Merle', 'V.', ''], dtype=object)
array(['Montero', 'J. C.', ''], dtype=object)
array(['Pereira', 'J. G.', ''], dtype=object)]
|
18,471 |
1109.5286
|
Dimitrios Giannakis
|
Peter Schwander, Chun Hong Yoon, Abbas Ourmazd, and Dimitrios
Giannakis
|
The symmetries of image formation by scattering. II. Applications
|
12 pages, 47 references, 6 figures, 5 tables. Movies available at
http://www.cims.nyu.edu/~dimitris
| null | null | null |
physics.comp-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show that the symmetries of image formation by scattering enable
graph-theoretic manifold-embedding techniques to extract structural and timing
information from simulated and experimental snapshots at extremely low signal.
The approach constitutes a physically-based, computationally efficient, and
noise-robust route to analyzing the large and varied datasets generated by
existing and emerging methods for studying structure and dynamics by
scattering. We demonstrate three-dimensional structure recovery from X-ray
diffraction and cryo-electron microscope image snapshots of unknown
orientation, the latter at 12 times lower dose than currently in use. We also
show that ultra-low-signal, random sightings of dynamically evolving systems
can be sequenced into high quality movies to reveal their evolution. Our
approach offers a route to recovering timing information in time-resolved
experiments, and extracting 3D movies from two-dimensional random sightings of
dynamic systems.
|
[{'version': 'v1', 'created': 'Sat, 24 Sep 2011 16:43:04 GMT'}]
|
2011-09-27
|
[array(['Schwander', 'Peter', ''], dtype=object)
array(['Yoon', 'Chun Hong', ''], dtype=object)
array(['Ourmazd', 'Abbas', ''], dtype=object)
array(['Giannakis', 'Dimitrios', ''], dtype=object)]
|
18,472 |
1805.11083
|
Francesc Wilhelmi
|
Francesc Wilhelmi, Sergio Barrachina-Mu\~noz, Cristina Cano, Boris
Bellalta, Anders Jonsson, Gergely Neu
|
Potential and Pitfalls of Multi-Armed Bandits for Decentralized Spatial
Reuse in WLANs
| null | null |
10.1016/j.jnca.2018.11.006
| null |
cs.NI
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Spatial Reuse (SR) has recently gained attention to maximize the performance
of IEEE 802.11 Wireless Local Area Networks (WLANs). Decentralized mechanisms
are expected to be key in the development of SR solutions for next-generation
WLANs, since many deployments are characterized by being uncoordinated by
nature. However, the potential of decentralized mechanisms is limited by the
significant lack of knowledge with respect to the overall wireless environment.
To shed some light on this subject, we show the main considerations and
possibilities of applying online learning to address the SR problem in
uncoordinated WLANs. In particular, we provide a solution based on Multi-Armed
Bandits (MABs) whereby independent WLANs dynamically adjust their frequency
channel, transmit power and sensitivity threshold. To that purpose, we provide
two different strategies, which refer to selfish and environment-aware
learning. While the former stands for pure individual behavior, the second one
considers the performance experienced by surrounding networks, thus taking into
account the impact of individual actions on the environment. Through these two
strategies we delve into practical issues of applying MABs in wireless
networks, such as convergence guarantees or adversarial effects. Our simulation
results illustrate the potential of the proposed solutions for enabling SR in
future WLANs. We show that substantial improvements on network performance can
be achieved regarding throughput and fairness.
|
[{'version': 'v1', 'created': 'Mon, 28 May 2018 17:52:26 GMT'}
{'version': 'v2', 'created': 'Mon, 11 Jun 2018 17:18:04 GMT'}
{'version': 'v3', 'created': 'Fri, 14 Dec 2018 15:09:07 GMT'}]
|
2018-12-17
|
[array(['Wilhelmi', 'Francesc', ''], dtype=object)
array(['Barrachina-Muñoz', 'Sergio', ''], dtype=object)
array(['Cano', 'Cristina', ''], dtype=object)
array(['Bellalta', 'Boris', ''], dtype=object)
array(['Jonsson', 'Anders', ''], dtype=object)
array(['Neu', 'Gergely', ''], dtype=object)]
|
18,473 |
1401.0616
|
Colin Cotter
|
C.J. Cotter and A.T.T. McRae
|
Compatible finite element methods for numerical weather prediction
|
To appear in ECMWF Seminar proceedings 2014
| null | null | null |
math.NA physics.ao-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This article takes the form of a tutorial on the use of a particular class of
mixed finite element methods, which can be thought of as the finite element
extension of the C-grid staggered finite difference method. The class is often
referred to as compatible finite elements, mimetic finite elements, discrete
differential forms or finite element exterior calculus. We provide an
elementary introduction in the case of the one-dimensional wave equation,
before summarising recent results in applications to the rotating shallow water
equations on the sphere, before taking an outlook towards applications in
three-dimensional compressible dynamical cores.
|
[{'version': 'v1', 'created': 'Fri, 3 Jan 2014 10:20:07 GMT'}]
|
2014-01-06
|
[array(['Cotter', 'C. J.', ''], dtype=object)
array(['McRae', 'A. T. T.', ''], dtype=object)]
|
18,474 |
2210.14368
|
Craig Hogle
|
Craig W. Hogle, Daniel Dominguez, Mark Dong, Andrew Leenheer, Hayden
J. McGuinness, Brandon P. Ruzic, Matthew Eichenfield, Daniel Stick
|
High-fidelity trapped-ion qubit operations with scalable photonic
modulators
| null | null | null | null |
quant-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Experiments with trapped ions and neutral atoms typically employ optical
modulators in order to control the phase, frequency, and amplitude of light
directed to individual atoms. These elements are expensive, bulky, consume
substantial power, and often rely on free-space I/O to deliver light to ions,
all of which pose scaling challenges. To support many-ion systems like trapped
ion quantum computers, as well as miniaturized deployable devices like clocks
and sensors, these elements must ultimately be microfabricated, ideally
monolithically with the trap to avoid losses associated with optical coupling
between physically separate components. In this work we design and fabricate an
optical modulator capable of monolithic integration with a surface-electrode
ion trap, demonstrating the first modulator technology capable of supporting
scalable trapped-ion quantum computing. Tested here on separate chips, these
devices consist of piezo-optomechanical photonic integrated circuits configured
as multi-stage Mach-Zehnder modulators that are used to control the intensity
of light delivered to a single trapped ion. We use quantum tomography employing
hundreds of multi-gate sequences to enhance the sensitivity of the fidelity to
the types and magnitudes of gate errors relevant to quantum computing and
better characterize the performance of the modulators, ultimately measuring
single qubit gate fidelities that exceed 99.7%.
|
[{'version': 'v1', 'created': 'Tue, 25 Oct 2022 22:22:11 GMT'}]
|
2022-10-27
|
[array(['Hogle', 'Craig W.', ''], dtype=object)
array(['Dominguez', 'Daniel', ''], dtype=object)
array(['Dong', 'Mark', ''], dtype=object)
array(['Leenheer', 'Andrew', ''], dtype=object)
array(['McGuinness', 'Hayden J.', ''], dtype=object)
array(['Ruzic', 'Brandon P.', ''], dtype=object)
array(['Eichenfield', 'Matthew', ''], dtype=object)
array(['Stick', 'Daniel', ''], dtype=object)]
|
18,475 |
0801.4269
|
Luciano da Fontoura Costa
|
Luciano da Fontoura Costa
|
Detecting Neuronal Communities from Beginning of Activation Patterns
|
9 pages, 7 figures. A working manuscript: suggestions and comments
welcomed
| null | null | null |
physics.soc-ph cond-mat.dis-nn physics.comp-ph q-bio.NC
| null |
The detection of neuronal communities is addressed with basis on two
important concepts from neuroscience: facilitation of neuronal firing and
nearly simultaneous beginning of activation of sets of neurons. More
specifically, integrate-and-fire complex neuronal networks are activated at
each of their nodes, and the dissemination of activation is monitored. As the
activation received by each neuron accumulates, its firing gets facilitated.
The time it takes for each neuron, other than the source, to receive the first
non-zero input (beginning activation time) and the time for it to produce the
first spike (beginning spiking time) are identified through simulations. It is
shown, with respect to two synthetic and a real-world (\emph{C. elegans})
neuronal complex networks, that the patterns of beginning activation times (and
to a lesser extent also of the spiking times) tend to cluster into groups
corresponding to communities of neurons in the original complex neuronal
network. Such an effect is identified to be a direct consequence of the almost
simultaneous activation between the nodes inside the same community in which
the source of activation is placed, as well as of the respective trapping of
activation implied by the integration of activiation prior to firing.
Interestingly, the accumulation of activity and thresholds inside each neuron
were found to be essential for constraining the initial activations within each
respective community during the transient activation (no clear clusters were
observed when using overall activation or spiking rates). In addition to its
intrinsic value for neuroscience and structure-dynamics studies, these results
confirm the importance of the consideration of transient dynamics in complex
systems investigations.
|
[{'version': 'v1', 'created': 'Mon, 28 Jan 2008 13:52:57 GMT'}]
|
2008-01-29
|
[array(['Costa', 'Luciano da Fontoura', ''], dtype=object)]
|
18,476 |
1207.3139
|
Fabio M. S. Lima
|
F. M. S. Lima
|
A rapidly converging Ramanujan-type series for Catalan's constant
|
Improved version of the previous manuscript, with revised text and
small corrections. 11 pages, 1 table. Submitted (06/03/2017)
| null | null | null |
math.NT
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this note, by making use of a known hypergeometric series identity, I
prove two Ramanujan-type series for the Catalan's constant. The convergence
rate of these central binomial series surpasses those of all known similar
series, including a classical formula by Ramanujan and a recent formula by
Lupas. Interestingly, this suggests that an Ap\'{e}ry-like irrationality proof
could be found for this constant.
|
[{'version': 'v1', 'created': 'Fri, 13 Jul 2012 03:18:38 GMT'}
{'version': 'v2', 'created': 'Sat, 3 Jun 2017 04:30:05 GMT'}]
|
2017-06-06
|
[array(['Lima', 'F. M. S.', ''], dtype=object)]
|
18,477 |
astro-ph/9904337
|
D. J. Macomb
|
D. J. Macomb (1,2), M. H. Finger (2,3), B. A. Harmon(3), R.C. Lamb (4)
and T. A. Prince (4) ((1) NASA/GSFC, (2) USRA, (3) NASA/MSFC, (4) Caltech)
|
Discovery of Pulsed X-ray Emission from the SMC Transient RX
J0117.6-7330
|
17 pages, Latex, aasms, accepted for publication in ApJ Letters
| null |
10.1086/312074
| null |
astro-ph
| null |
We report on the detection of pulsed, broad-band, X-ray emission from the
transient source RX J0117.6-7330. The pulse period of 22 seconds is detected by
the ROSAT/PSPC instrument in a 1992 Sep 30 - Oct 2 observation and by the
CGRO/BATSE instrument during the same epoch. Hard X-ray pulsations are
detectable by BATSE for approximately 100 days surrounding the ROSAT
observation (1992 Aug 28 - Dec 8). The total directly measured X-ray luminosity
during the ROSAT observation is 1.0E38 (d/60 kpc)^2 ergs s-1. The pulse
frequency increases rapidly during the outburst, with a peak spin-up rate of
1.2E-10 Hz s-1 and a total frequency change 1.8%. The pulsed percentage is
11.3% from 0.1-2.5 keV, increasing to at least 78% in the 20-70 keV band. These
results establish RX J0117.6-7330 as a transient Be binary system.
|
[{'version': 'v1', 'created': 'Fri, 23 Apr 1999 21:14:42 GMT'}]
|
2009-10-31
|
[array(['Macomb', 'D. J.', '', 'NASA/GSFC', 'USRA'], dtype=object)
array(['Finger', 'M. H.', '', 'USRA', 'NASA/MSFC'], dtype=object)
array(['Harmon', 'B. A.', '', 'NASA/MSFC'], dtype=object)
array(['Lamb', 'R. C.', '', 'Caltech'], dtype=object)
array(['Prince', 'T. A.', '', 'Caltech'], dtype=object)]
|
18,478 |
1410.7822
|
Daniel Munoz-Alvarez
|
Daniel Munoz-Alvarez and Eilyan Bitar
|
Financial Storage Rights in Electric Power Networks
|
24 pages
| null | null | null |
math.OC
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The decreasing cost of energy storage technologies coupled with their
potential to bring significant benefits to electric power networks have kindled
research efforts to design both market and regulatory frameworks to facilitate
the efficient construction and operation of such technologies. In this paper,
we examine an open access approach to the integration of storage, which enables
the complete decoupling of a storage facility's ownership structure from its
operation. In particular, we analyze a nodal spot pricing system built on a
model of economic dispatch in which storage is centrally dispatched by the
independent system operator (ISO) to maximize social welfare. Concomitant with
such an approach is the ISO's collection of a merchandising surplus reflecting
congestion in storage. We introduce a class of tradable electricity derivatives
---referred to as financial storage rights (FSRs)--- to enable the
redistribution of such rents in the form of financial property rights to
storage capacity; and establish a generalized simultaneous feasibility test to
ensure the ISO's revenue adequacy when allocating such financial property
rights to market participants. Several advantages of such an approach to open
access storage are discussed. In particular, we illustrate with a stylized
example the role of FSRs in synthesizing fully hedged, fixed-price bilateral
contracts for energy, when the seller and buyer exhibit differing intertemporal
supply and demand characteristics, respectively.
|
[{'version': 'v1', 'created': 'Tue, 28 Oct 2014 21:40:55 GMT'}
{'version': 'v2', 'created': 'Thu, 5 Mar 2015 23:28:13 GMT'}
{'version': 'v3', 'created': 'Wed, 14 Sep 2016 00:41:23 GMT'}
{'version': 'v4', 'created': 'Fri, 31 Mar 2017 04:08:13 GMT'}]
|
2017-04-03
|
[array(['Munoz-Alvarez', 'Daniel', ''], dtype=object)
array(['Bitar', 'Eilyan', ''], dtype=object)]
|
18,479 |
1607.03608
|
Wendy Lowen
|
Wendy Lowen, Julia Ramos Gonz\'alez and Boris Shoikhet
|
On the tensor product of linear sites and Grothendieck categories
|
New sections 5.3 on the alpha-Deligne tensor product and 5.4 on
future prospects
| null | null | null |
math.CT
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We define a tensor product of linear sites, and a resulting tensor product of
Grothendieck categories based upon their representations as categories of
linear sheaves. We show that our tensor product is a special case of the tensor
product of locally presentable linear categories, and that the tensor product
of locally coherent Grothendieck categories is locally coherent if and only if
the Deligne tensor product of their abelian categories of finitely presented
objects exists. We describe the tensor product of non-commutative projective
schemes in terms of Z-algebras, and show that for projective schemes our tensor
product corresponds to the usual product scheme.
|
[{'version': 'v1', 'created': 'Wed, 13 Jul 2016 07:03:32 GMT'}
{'version': 'v2', 'created': 'Wed, 30 Nov 2016 21:10:31 GMT'}
{'version': 'v3', 'created': 'Wed, 15 Mar 2017 17:57:35 GMT'}]
|
2017-03-16
|
[array(['Lowen', 'Wendy', ''], dtype=object)
array(['González', 'Julia Ramos', ''], dtype=object)
array(['Shoikhet', 'Boris', ''], dtype=object)]
|
18,480 |
hep-th/9310007
|
Roger Brooks
|
R. Brooks
|
The Cosmological Constant and Volume-Preserving Diffeomorphism
Invariants
|
31 pgs, 3 figs (seperate file), Latex, CTP-2247
|
Nucl.Phys. B423 (1994) 197-220
|
10.1016/0550-3213(94)90570-3
| null |
hep-th
| null |
Observables in the quantum field theories of $(D-1)$-form fields, $\ca$, on
$D$-dimensional, compact and orientable manifolds, $M$, are computed.
Computations of the vacuum value of $T_{ab}$ find it to be the metric times a
function of the volume of spacetime, $\Omega(M)$. Part of this function of
$\Omega$ is a finite zero-mode contribution. The correlation functions of
another set of operators give intersection numbers on $M$. Furthermore, a
similar computation for products of Wilson area operators results in a function
of the volumes of the intersections of the submanifolds the operators are
defined on. In addition, scalar field couplings are introduced and potentials
are induced after integrating out the $\ca$ field. Lastly, the thermodynamics
of the pure theories is found to be analogous to the zero-point motion of a
scalar particle. The coupling of a Gaussian scalar field to the $\ca$ field is
found to manifest itself on the free energy at high temperatures and/or small
volumes.
|
[{'version': 'v1', 'created': 'Fri, 1 Oct 1993 15:30:11 GMT'}
{'version': 'v2', 'created': 'Mon, 4 Oct 1993 14:54:07 GMT'}
{'version': 'v3', 'created': 'Thu, 4 Nov 1993 14:18:57 GMT'}]
|
2016-09-06
|
[array(['Brooks', 'R.', ''], dtype=object)]
|
18,481 |
1309.1809
|
Jiang Daijun
|
Jiang Daijun, Feng Hui and Zou Jun
|
Overlapping Domain Decomposition Methods for Linear Inverse Problems
|
25 pages, 8 figures, 8 Tables
| null | null | null |
math.NA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We shall derive and propose several efficient overlapping domain
decomposition methods for solving some typical linear inverse problems,
including the identiffication of the flux, the source strength and the initial
temperature in second order elliptic and parabolic systems. The methods are
iterative, and computationally very efficient: only local forward and adjoint
problems need to be solved in each subdomain, and the local minimizations have
explicit solutions. Numerical experiments are provided to demonstrate the
robustness and efficiency of the methods, in particular, the convergences seem
nearly optimal, i.e., they do not deteriorate or deteriorate only slightly when
the mesh size reduces.
|
[{'version': 'v1', 'created': 'Sat, 7 Sep 2013 02:49:32 GMT'}]
|
2013-09-10
|
[array(['Daijun', 'Jiang', ''], dtype=object)
array(['Hui', 'Feng', ''], dtype=object)
array(['Jun', 'Zou', ''], dtype=object)]
|
18,482 |
hep-ph/9901451
|
W. James Stirling
|
K. Philippides and W.J. Stirling
|
Restoring good high energy behaviour in Higgs production via W fusion at
the LHC
|
32 pages, Latex, 11 figures as postscript files
|
Eur.Phys.J.C9:181-195,1999
|
10.1007/s100529900050
|
DTP/98/46
|
hep-ph
| null |
The W-fusion scattering process W+W- --> ZZ for off-shell W bosons is
studied, focusing on the issue of its high-energy behaviour which is known to
be anomalous. It is shown that the unitarity violating terms can be isolated
and extracted in a well-defined and efficient way using the pinch-technique.
This restores the good high energy behaviour of the cross section and, in
particular, makes possible the identification of the Higgs resonance in the
invariant mass distribution M(ZZ) of the Z pair. The discarded terms, which are
proportional to the off-shellness of the W bosons, cancel against similar terms
originating from the remaining diagrams for the full physical process f1 f2 -->
f1' f2' Z Z. This cancellation ensures the gauge invariance of our result,
which therefore constitutes a meaningful separation between signal and
background when they both contribute coherently. Equipped with this result, we
are able to define a resonant approximation for the process p p --> Z Z + 2
jets + X, which circumvents the problem of good high energy behaviour without
having to resort to the lengthy calculation of the complete set of diagrams. In
this approximation only the W and Z fusion signal graphs are included, i.e. the
ones which contain the Higgs resonance. We have verified that the approximate
resonant cross section describes very well the full result not only close to
the resonance but also beyond it.
|
[{'version': 'v1', 'created': 'Fri, 29 Jan 1999 16:41:25 GMT'}]
|
2011-09-13
|
[array(['Philippides', 'K.', ''], dtype=object)
array(['Stirling', 'W. J.', ''], dtype=object)]
|
18,483 |
2012.01317
|
Colm Talbot
|
Colm Talbot and Eric Thrane
|
Fast, flexible, and accurate evaluation of gravitational-wave Malmquist
bias with machine learning
|
11 pages, 6 figures, accompanying code at
https://github.com/ColmTalbot/gmm_sensitivity_estimation
| null | null | null |
gr-qc astro-ph.HE astro-ph.IM
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Many astronomical surveys are limited by the brightness of the sources, and
gravitational-wave searches are no exception. The detectability of
gravitational waves from merging binaries is affected by the mass and spin of
the constituent compact objects. To perform unbiased inference on the
distribution of compact binaries, it is necessary to account for this selection
effect, which is known as Malmquist bias. Since systematic error from selection
effects grows with the number of events, it will be increasingly important over
the coming years to accurately estimate the observational selection function
for gravitational-wave astronomy. We employ density estimation methods to
accurately and efficiently compute the compact binary coalescence selection
function. We introduce a simple pre-processing method, which significantly
reduces the complexity of the required machine learning models. We demonstrate
that our method has smaller statistical errors at comparable computational cost
than the method currently most widely used allowing us to probe narrower
distributions of spin magnitudes. The currently used method leaves $10-50\%$ of
the interesting black hole spin models inaccessible; our new method can probe
$>99\%$ of the models and has a lower uncertainty for $>80\%$ of the models.
|
[{'version': 'v1', 'created': 'Wed, 2 Dec 2020 16:42:44 GMT'}
{'version': 'v2', 'created': 'Tue, 29 Jun 2021 21:35:43 GMT'}
{'version': 'v3', 'created': 'Sun, 2 Jan 2022 14:20:39 GMT'}]
|
2022-01-04
|
[array(['Talbot', 'Colm', ''], dtype=object)
array(['Thrane', 'Eric', ''], dtype=object)]
|
18,484 |
1703.02459
|
Loren Coquille
|
Anton Bovier, Loren Coquille, Rebecca Neukirch
|
The recovery of a recessive allele in a Mendelian diploid model
|
49 pages, revised version
| null | null | null |
math.PR q-bio.PE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the large population limit of a stochastic individual-based model
which describes the time evolution of a diploid hermaphroditic population
reproducing according to Mendelian rules. In [Neukirch, Bovier, 2016] it is
proved that sexual reproduction allows unfit alleles to survive in individuals
with mixed genotype much longer than they would in populations reproducing
asexually. In the present paper we prove that this indeed opens the possibility
that individuals with a pure genotype can reinvade in the population after the
appearance of further mutations. We thus expose a formal description of a
mechanism by which a recessive allele can re-emerge in a population. This can
be seen as a statement of genetic robustness exhibited by diploid populations
performing sexual reproduction.
|
[{'version': 'v1', 'created': 'Tue, 7 Mar 2017 16:33:48 GMT'}
{'version': 'v2', 'created': 'Fri, 2 Jun 2017 15:40:20 GMT'}
{'version': 'v3', 'created': 'Sat, 20 Jan 2018 18:17:58 GMT'}]
|
2018-01-23
|
[array(['Bovier', 'Anton', ''], dtype=object)
array(['Coquille', 'Loren', ''], dtype=object)
array(['Neukirch', 'Rebecca', ''], dtype=object)]
|
18,485 |
2303.12503
|
Pedro C.S. Costa
|
Peyman Najafi, Pedro C.S. Costa and Dominic W. Berry
|
Optimum phase estimation with two control qubits
|
11 pages, 7 figures. Paper sent for Jonathan P. Dowling Memorial
Special Issue
| null | null | null |
quant-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Phase estimation is used in many quantum algorithms, particularly in order to
estimate energy eigenvalues for quantum systems. When using a single qubit as
the probe (used to control the unitary we wish to estimate the eigenvalue of),
it is not possible to measure the phase with a minimum mean-square error. In
standard methods, there would be a logarithmic (in error) number of control
qubits needed in order to achieve this minimum error. Here show how to perform
this measurement using only two control qubits, thereby reducing the qubit
requirements of the quantum algorithm. Our method corresponds to preparing the
optimal control state one qubit at a time, while it is simultaneously consumed
by the measurement procedure.
|
[{'version': 'v1', 'created': 'Wed, 22 Mar 2023 12:18:33 GMT'}]
|
2023-03-23
|
[array(['Najafi', 'Peyman', ''], dtype=object)
array(['Costa', 'Pedro C. S.', ''], dtype=object)
array(['Berry', 'Dominic W.', ''], dtype=object)]
|
18,486 |
1511.03437
|
Zenro Hioki
|
Zenro Hioki (U. Tokushima) and Kazumasa Ohkuma (Okayama U. Science)
|
Full analysis of general non-standard tbW couplings
|
One comment and two related references added. Final version to appear
in Phys.Lett.B
|
Physics Letters B752 (2016) 128
|
10.1016/j.physletb.2015.11.029
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Possible non-standard couplings which could contribute to the t -> b W
process are studied based on the effective-Lagrangian approach. The
corresponding effective Lagrangian consists of four kinds of dimension-6
effective operators, each of which has an independent coupling constant. In
this analysis, all those couplings are treated as complex numbers and
constraints on them are estimated by using recent experimental data from the
LHC. We point out that the resultant constraints on those couplings are still
not that strong because contributions from some couplings can work oppositely
with each other.
|
[{'version': 'v1', 'created': 'Wed, 11 Nov 2015 10:08:34 GMT'}
{'version': 'v2', 'created': 'Tue, 17 Nov 2015 03:09:02 GMT'}]
|
2015-11-24
|
[array(['Hioki', 'Zenro', '', 'U. Tokushima'], dtype=object)
array(['Ohkuma', 'Kazumasa', '', 'Okayama U. Science'], dtype=object)]
|
18,487 |
1103.1794
|
Evgeny Schneidmiller
|
M. Dohlus, E.A. Schneidmiller and M.V. Yurkov
|
Generation of attosecond soft x-ray pulses in a longitudinal space
charge amplifier
| null | null |
10.1103/PhysRevSTAB.14.090702
|
DESY 11-040
|
physics.acc-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A longitudinal space charge amplifier (LSCA), operating in soft x-ray regime,
was recently proposed. Such an amplifier consists of a few amplification
cascades (focusing channel and chicane) and a short radiator undulator in the
end. Broadband nature of LSCA supports generation of few-cycle pulses as well
as wavelength compression. In this paper we consider an application of these
properties of LSCA for generation of attosecond x-ray pulses. It is shown that
a compact and cheap addition to the soft x-ray free electron laser facility
FLASH would allow to generate 60 attosecond (FWHM) long x-ray pulses with the
peak power at 100 MW level and a contrast above 98%.
|
[{'version': 'v1', 'created': 'Wed, 9 Mar 2011 14:35:23 GMT'}]
|
2013-05-29
|
[array(['Dohlus', 'M.', ''], dtype=object)
array(['Schneidmiller', 'E. A.', ''], dtype=object)
array(['Yurkov', 'M. V.', ''], dtype=object)]
|
18,488 |
1801.04027
|
Bahareh Momenan
|
Bahareh Momenan (1), Michel R. Labrosse (2) ((1,2) Department of
Mechanical Engineering, University of Ottawa)
|
A New Continuum-Based Thick Shell Finite Element for Soft Biological
Tissues in Dynamics: Part 2 - Anisotropic Hyperelasticity and
Incompressibility Aspects
|
16 pages, 17 figures
| null | null | null |
math.NA physics.bio-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In a companion article (Part 1), we presented the development of a thick
continuum-based (CB) shell finite element (FE) based on Mindlin-Reissner
theory. We verified the accuracy, efficiency and locking insensitivity of the
element in modeling large 3D deformations, using linear elastic material
properties. In the present article, we developed and implemented the kinetics
description, within the updated Lagrangian (UL) formulation, of anisotropic
incompressible hyperelastic constitutive relations that enable the CB shell FE
to accurately model very large 3D strains and deformations. Specifically, we
developed the measures of deformation in the lamina coordinate system,
presented three techniques to model nonlinear hyperelastic strains, and enabled
the direct enforcement of incompressibility and of the zero normal stress
condition without using a penalty factor or a Lagrange multiplier. Moving
towards the application of the present work to the biomedical realm, we
performed multiple experiments concerning mechanical behavior of rubber-like
materials and soft biological tissues in different geometries and loading
conditions. Excellent agreements between the present FE results and the
analytical and/or experimental data proved the CB shell FE combined with the
present constitutive techniques to be a highly reliable and efficient tool for
modeling, analyzing, and predicting mechanical behavior of soft biological
tissues.
|
[{'version': 'v1', 'created': 'Fri, 12 Jan 2018 01:02:31 GMT'}]
|
2018-01-15
|
[array(['Momenan', 'Bahareh', ''], dtype=object)
array(['Labrosse', 'Michel R.', ''], dtype=object)]
|
18,489 |
1905.07983
|
Michael Voit
|
Kilian Hermann, Michael Voit
|
Limit theorems for Jacobi ensembles with large parameters
|
The presentation of the results is improved, and additional
references are added
|
Tunisian J. Math. 3 (2021) 843-860
|
10.2140/tunis.2021.3.843
| null |
math.PR math-ph math.MP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Consider Jacobi random matrix ensembles with the distributions
$$c_{k_1,k_2,k_3}\prod_{1\leq i< j \leq
N}\left(x_j-x_i\right)^{k_3}\prod_{i=1}^N
\left(1-x_i\right)^{\frac{k_1+k_2}{2}-\frac{1}{2}}\left(1+x_i\right)^{\frac{k_2}{2}-\frac{1}{2}}
dx$$ of the eigenvalues on the alcoves $$A:=\{x\in\mathbb R^N| \> -1\leq x_1\le
...\le x_N\leq 1\}.$$ For $(k_1,k_2,k_3)=\kappa\cdot (a,b,1)$ with $a,b>0$
fixed, we derive a central limit theorem for the distributions above for
$\kappa\to\infty$. The drift and the inverse of the limit covariance matrix are
expressed in terms of the zeros of classical Jacobi polynomials. We also
rewrite the CLT in trigonometric form and determine the eigenvalues and
eigenvectors of the limit covariance matrices. These results are related to
corresponding limits for $\beta$-Hermite and $\beta$-Laguerre ensembles for
$\beta\to\infty$ by Dumitriu and Edelman and by Voit.
|
[{'version': 'v1', 'created': 'Mon, 20 May 2019 10:44:37 GMT'}
{'version': 'v2', 'created': 'Thu, 15 Oct 2020 09:42:03 GMT'}]
|
2021-10-27
|
[array(['Hermann', 'Kilian', ''], dtype=object)
array(['Voit', 'Michael', ''], dtype=object)]
|
18,490 |
1206.1338
|
Anzhong Wang
|
Kai Lin, Shinji Mukohyama, and Anzhong Wang
|
Solar system tests and interpretation of gauge field and Newtonian
prepotential in general covariant Ho\v{r}ava-Lifshitz gravity
|
revtex4, 16 pages without figures. Phys. Rev. D86, 104024 (2012)
| null |
10.1103/PhysRevD.86.104024
|
IPMU12-0115
|
hep-th astro-ph.CO gr-qc hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study spherically symmetric, stationary vacuum configurations in general
covariant theory (U(1) extension) of Ho\v{r}ava-Lifshitz gravity with the
projectability condition and an arbitrary coupling constant $\lambda$, and
obtain all the solutions in closed forms. If the gauge field $A$ and the
Newtonian prepotential $\varphi$ do not directly couple to matter fields, the
theory is inconsistent with solar system tests for $\lambda\not=1$, no matter
how small $|\lambda-1|$ is. This is shown to be true also with the most general
ansatz of spherical (but not necessarily stationary) configurations. Therefore,
to be consistent with observations, one needs either to find a mechanism to
restrict $\lambda$ precisely to $\lambda_{GR}=1$, or to consider $A$ and/or
$\varphi$ as parts of the 4-dimensional metric on which matter fields
propagate. In the latter, requiring that the line element be invariant not only
under the foliation-preserving diffeomorphism but also under the local U(1)
transformations, we propose the replacements, $N \rightarrow N - \upsilon(A -
{\cal{A}})/c^2$ and $N^i \rightarrow N^i+N\nabla^{i}\varphi$, where $\upsilon$
is a dimensionless coupling constant to be constrained by observations, $N$ and
$N^i$ are, respectively, the lapse function and shift vector, and ${\cal{A}}
\equiv - \dot{\varphi} + N^i\nabla_{i}\varphi + N(\nabla_{i}\varphi)^2/2$. With
this prescription, we show explicitly that the aforementioned solutions are
consistent with solar system tests for both $\lambda=1$ and $\lambda\not=1$,
provided that $|\upsilon-1|<10^{-5}$. From this result, the physical and
geometrical interpretations of the fields $A$ and $\varphi$ become clear.
However, it still remains to be understood how to obtain such a prescription
from the action principle.
|
[{'version': 'v1', 'created': 'Wed, 6 Jun 2012 20:11:01 GMT'}
{'version': 'v2', 'created': 'Wed, 17 Oct 2012 14:35:45 GMT'}
{'version': 'v3', 'created': 'Mon, 7 Jan 2013 01:58:41 GMT'}]
|
2015-06-05
|
[array(['Lin', 'Kai', ''], dtype=object)
array(['Mukohyama', 'Shinji', ''], dtype=object)
array(['Wang', 'Anzhong', ''], dtype=object)]
|
18,491 |
1210.2965
|
Fabian Schmidt
|
Fabian Schmidt, Lam Hui
|
CMB Power Asymmetry from Non-Gaussian Modulation
|
4+epsilon pages, 1 figure; v2: minor edits and references added,
reflects PRL version in press
|
Phys. Rev. Lett. 110, 011301 (2013)
|
10.1103/PhysRevLett.110.011301
| null |
astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Non-Gaussianity in the inflationary perturbations can couple observable
scales to modes of much longer wavelength (even superhorizon), leaving as a
signature a large-angle modulation of the observed cosmic microwave background
(CMB) power spectrum. This provides an alternative origin for a power asymmetry
which is otherwise often ascribed to a breaking of statistical isotropy. The
non-Gaussian modulation effect can be significant even for typical ~10^{-5}
perturbations, while respecting current constraints on non-Gaussianity, if the
squeezed limit of the bispectrum is sufficiently infrared divergent. Just such
a strongly infrared-divergent bispectrum has been claimed for inflation models
with a non-Bunch-Davies initial state, for instance. Upper limits on the
observed CMB power asymmetry place stringent constraints on the duration of
inflation in such models.
|
[{'version': 'v1', 'created': 'Wed, 10 Oct 2012 16:05:23 GMT'}
{'version': 'v2', 'created': 'Fri, 14 Dec 2012 20:24:11 GMT'}]
|
2013-05-30
|
[array(['Schmidt', 'Fabian', ''], dtype=object)
array(['Hui', 'Lam', ''], dtype=object)]
|
18,492 |
2204.05844
|
Merlin Kole
|
Merlin Kole, Jianchao Sun
|
Gamma-ray Polarimetry of Transient Sources with POLAR
|
37 pages, 16 figures, Invited Chapter accepted to appear in
Springer's "Handbook of X-ray and Gamma-ray Astrophysics"
| null |
10.1007/978-981-16-4544-0_142-1
| null |
astro-ph.IM astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Polarization measurements of the gamma-ray component of transient sources are
of great scientific interest, they are however, also highly challenging. This
is due to the typical low signal to noise and the potential for significant
systematic errors. Both issues are made worse by the transient nature of the
events which prompt one to observe a large portion of the sky. The POLAR
instrument was designed as a dedicated transient gamma-ray polarimeter. It made
use of a large effective area and large field of view to maximize the signal to
noise as well as the number of observed transients. Additionally, it was
calibrated carefully on ground and in orbit to mitigate systematic errors. The
main scientific goal of POLAR was to measure the polarization of the prompt
emission of Gamma-Ray Bursts. During the 6 months operation in orbit POLAR
observed 55 Gamma-Ray Bursts of which 14 were bright enough to allow for
constraining polarization measurements. In this chapter we mainly discuss about
the POLAR instrument along with the calibration and analysis procedures. Two
analyses are described, the first is a straightforward method previously
implemented in polarization measurements, whilst the second was developed to
improve the sensitivity and to mitigate several of the issues with the former.
Both methods are described in detail along with information on how these can be
extended to perform time and energy resolved polarization measurements.
|
[{'version': 'v1', 'created': 'Tue, 12 Apr 2022 14:44:29 GMT'}]
|
2023-04-05
|
[array(['Kole', 'Merlin', ''], dtype=object)
array(['Sun', 'Jianchao', ''], dtype=object)]
|
18,493 |
hep-ph/9905457
|
Ray Subharthi
|
Jishnu Dey, Siddhartha Bhowmik, Kanad Ray and Subharthi Ray
|
Limiting temperature of hadrons using states predicted from
kappa-deformed Poincar\'e algebra
|
7 Latex pages including two figures
|
Indian J.Phys. 73B (1999) 409-415
| null | null |
hep-ph
| null |
The experimental hadronic density of states dN/dm, assumed to be a sum of
normalized Breit- Wigner distributions and plotted as a function of the hadron
mass m, fails to show a Hagedorn like growth beyond 2 GeV, probably due to a
lack of data. Experimental hadronic states are fitted using $\ka$ -deformed
Poincar\'e algebra and the fit is used to extrapolate for including states not
detected. For the theoretical density of states the plot is a straight line in
the log scale even beyond 2 GeV with a limiting temperature of 400 MeV.
|
[{'version': 'v1', 'created': 'Sun, 23 May 1999 14:49:35 GMT'}]
|
2007-05-23
|
[array(['Dey', 'Jishnu', ''], dtype=object)
array(['Bhowmik', 'Siddhartha', ''], dtype=object)
array(['Ray', 'Kanad', ''], dtype=object)
array(['Ray', 'Subharthi', ''], dtype=object)]
|
18,494 |
2201.06962
|
Weiming Hu
|
Weiming Hu, Guido Cervone, Matteo Turilli, Andre Merzky, Shantenu Jha
|
A Scalable Solution for Running Ensemble Simulations for Photovoltaic
Energy
| null | null | null | null |
cs.CE cs.DC physics.ao-ph
|
http://creativecommons.org/licenses/by/4.0/
|
This chapter proposes and provides an in-depth discussion of a scalable
solution for running ensemble simulation for solar energy production.
Generating a forecast ensemble is computationally expensive. But with the help
of Analog Ensemble, forecast ensembles can be generated with a single
deterministic run of a weather forecast model. Weather ensembles are then used
to simulate 11 10 KW photovoltaic solar power systems to study the simulation
uncertainty under a wide range of panel configuration and weather conditions.
This computational workflow has been deployed onto the NCAR supercomputer,
Cheyenne, with more than 7,000 cores.
Results show that, spring and summer are typically associated with a larger
simulation uncertainty. Optimizing the panel configuration based on their
individual performance under changing weather conditions can improve the
simulation accuracy by more than 12%. This work also shows how panel
configuration can be optimized based on geographic locations.
|
[{'version': 'v1', 'created': 'Mon, 10 Jan 2022 22:40:50 GMT'}]
|
2022-01-19
|
[array(['Hu', 'Weiming', ''], dtype=object)
array(['Cervone', 'Guido', ''], dtype=object)
array(['Turilli', 'Matteo', ''], dtype=object)
array(['Merzky', 'Andre', ''], dtype=object)
array(['Jha', 'Shantenu', ''], dtype=object)]
|
18,495 |
1905.05411
|
Nicolas Holliman Professor
|
Richard Cloete, Nick Holliman
|
Measuring and simulating latency in interactive remote rendering systems
|
Minor update to typos and acknowledgements
| null | null | null |
cs.NI cs.DC cs.GR
|
http://creativecommons.org/licenses/by/4.0/
|
Background: The computationally intensive task of real-time rendering can be
offloaded to remote cloud systems. However, due to network latency, interactive
remote rendering (IRR) introduces the challenge of interaction latency (IL),
which is the time between an action and response to that action. Objectives: to
model sources of latency, measure it in a real-world network and to use this
understanding to simulate latency so that we have a controlled platform for
experimental work in latency management. Method: we present a seven-parameter
model of latency for a typical IRR system; we describe new, minimally intrusive
software methods for measuring latency in a 3D graphics environment and create
a novel latency simulator tool in software. Results: We demonstrate our latency
simulator is comparable to real-world behavior and confirm that real-world
latency exceeds the interactive limit of 70ms over long distance connections.
We also find that current approaches to measuring IL are not general enough for
most situations and therefore propose a novel general-purpose solution.
Conclusion: to ameliorate latency in IRR systems we need controllable
simulation tools for experimentation. In addition to a new measurement
technique, we propose a new approach that will be of interest to IRR
researchers and developers when designing IL compensation techniques.
|
[{'version': 'v1', 'created': 'Tue, 14 May 2019 06:38:36 GMT'}
{'version': 'v2', 'created': 'Sat, 18 May 2019 19:58:34 GMT'}]
|
2019-05-21
|
[array(['Cloete', 'Richard', ''], dtype=object)
array(['Holliman', 'Nick', ''], dtype=object)]
|
18,496 |
2105.01682
|
Mislav Balokovi\'c
|
M. Balokovi\'c, S. E. Cabral, L. Brenneman, C. M. Urry
|
Properties of the Obscuring Torus in NGC 1052 from Multi-epoch Broadband
X-ray Spectroscopy
|
20 pages, 9 figures; published in ApJ (vol. 916, id. 90); minor
update to match the final published version
|
ApJ, 916, 90 (2021)
|
10.3847/1538-4357/abff4d
| null |
astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Obscuration of the innermost parts of active galactic nuclei (AGN) is
observed in the majority of the population both in the nearby universe and at
high redshift. However, the nature of the structures causing obscuration,
especially in low-luminosity AGN, is poorly understood at present. We present a
novel approach to multi-epoch broadband X-ray spectroscopy, anchored in the
long-term average spectrum in the hard X-ray band, applied to the nearby, X-ray
bright AGN in the galaxy NGC 1052. From spectral features due to X-ray
reprocessing in the circumnuclear material, based on a simple, uniform-density
torus X-ray reprocessing model, we find a covering factor of 80-100% and a
globally averaged column density in the range (1-2) x 10^23 cm^-2. This closely
matches the independently measured variable line-of-sight column density range,
leading to a straightforward and self-consistent picture of the obscuring torus
in NGC 1052, similar to several other AGN in recent literature. Comparing this
X-ray-constrained torus model with measurements of spatially resolved
sub-parsec absorption from radio observations, we find that it may be possible
to account for both X-ray and radio data with a torus model featuring a steep
density gradient along the axis of the relativistic jets. This provides a
valuable direction for the development of improved physical models for the
circumnuclear environment in NGC 1052 and potentially in a wider class of AGN.
|
[{'version': 'v1', 'created': 'Tue, 4 May 2021 18:04:15 GMT'}
{'version': 'v2', 'created': 'Mon, 6 Sep 2021 14:15:53 GMT'}]
|
2021-09-07
|
[array(['Baloković', 'M.', ''], dtype=object)
array(['Cabral', 'S. E.', ''], dtype=object)
array(['Brenneman', 'L.', ''], dtype=object)
array(['Urry', 'C. M.', ''], dtype=object)]
|
18,497 |
hep-th/9802186
|
George Papadopoulos
|
J. Gutowski and G. Papadopoulos
|
The Moduli Spaces of Worldvolume Brane Solitons
|
13 pages, phyzzx
|
Phys.Lett.B432:97-102,1998
|
10.1016/S0370-2693(98)00608-X
|
DAMTP-R/98/10
|
hep-th
| null |
We compute the moduli metrics of worldvolume 0-brane solitons of D-branes and
the worldvolume self-dual string solitons of the M-5-brane and examine their
geometry. We find that the moduli spaces of 0-brane solitons of D-4-branes and
D-8-branes are hyper-K\"ahler manifolds with torsion and octonionic K\"ahler
manifolds with torsion, respectively. The moduli space of the self-dual string
soliton of the M-5-brane is also a hyper-K\"ahler manifold with torsion.
|
[{'version': 'v1', 'created': 'Thu, 26 Feb 1998 22:55:59 GMT'}]
|
2009-10-09
|
[array(['Gutowski', 'J.', ''], dtype=object)
array(['Papadopoulos', 'G.', ''], dtype=object)]
|
18,498 |
1805.00191
|
Dinh Thi Nguyen
|
Dinh-Thi Nguyen
|
Many-Body Blow-Up Profile of Boson Stars with External Potentials
|
To appear in Reviews in Mathematical Physics
| null |
10.1142/S0129055X1950034X
| null |
math-ph math.AP math.MP math.SP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a 3D quantum system of $N$ identical bosons in a trapping
potential $|x|^p$, with $p\geq0$, interacting via a Newton potential with an
attractive interaction strength $a_{N}$. For a fixed large $N$ and the coupling
constant $a_{N}$ smaller than a critical value $a_{*}$ (Chandrasekhar limit
mass), in an appropriate sense, the many-body system admits a ground state. We
investigate the blow-up behavior of the ground state energy as well as the
ground states when $a_{N}$ approaches $a_{*}$ sufficiently slowly in the limit
$N\to\infty$. The blow-up profile is given by the Gagliardo-Nirenberg
solutions.
|
[{'version': 'v1', 'created': 'Tue, 1 May 2018 05:15:23 GMT'}
{'version': 'v2', 'created': 'Tue, 12 Feb 2019 23:03:07 GMT'}
{'version': 'v3', 'created': 'Tue, 11 Jun 2019 15:31:40 GMT'}]
|
2019-06-12
|
[array(['Nguyen', 'Dinh-Thi', ''], dtype=object)]
|
18,499 |
astro-ph/9408002
|
Edward L. Wright
|
Edward L. Wright
|
Dark Matter in the Light of COBE
|
presented at the UCLA Dark matter conference, February 1994, 8 pages
of LaTex using aaspp.sty and epsf.sty with appended Postscript figures,
UCLA-ASTRO-ELW-94-01
| null | null | null |
astro-ph
| null |
The observations of all three COBE instruments are examined for the effects
of dark matter. The anisotropy measured by the DMR, and especially the
degree-scale ground- and balloon-based experiments, is only compatible with
large-scale structure formation by gravity if the Universe is dominated by
non-baryonic dark matter. The FIRAS instrument measures the total power
radiated by cold dust, and thus places tight limits on the absorption of
starlight by very cold gas and dust in the outer Milky Way. The DIRBE
instrument measures the infrared background, and will place tight limits on the
emission by low mass stars in the Galactic halo.
|
[{'version': 'v1', 'created': 'Mon, 1 Aug 1994 18:11:12 GMT'}]
|
2007-05-23
|
[array(['Wright', 'Edward L.', ''], dtype=object)]
|
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