Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Disk-satellite interaction in disks with density gaps   Gravitational coupling between a gaseous disk and an orbiting perturber leads
to angular momentum exchange between them which can result in gap opening by
planets in protoplanetary disks and clearing of gas by binary supermassive
black holes (SMBHs) embedded in accretion disks. Understanding the co-evolution
of the disk and the orbit of the perturber in these circumstances requires
knowledge of the spatial distribution of the torque exerted by the latter on a
highly nonuniform disk. Here we explore disk-satellite interaction in disks
with gaps in linear approximation both in Fourier and in physical space,
explicitly incorporating the disk non-uniformity in the fluid equations.
Density gradients strongly displace the positions of Lindblad resonances in the
disk (which often occur at multiple locations), and the waveforms of modes
excited close to the gap edge get modified compared to the uniform disk case.
The spatial distribution of the excitation torque density is found to be quite
different from the existing prescriptions: most of the torque is exerted in a
rather narrow region near the gap edge where Lindblad resonances accumulate,
followed by an exponential fall-off with the distance from the perturber.
Despite these differences, for a given gap profile the full integrated torque
exerted on the disk agrees with the conventional uniform disk theory prediction
at the level of ~10%. The nonlinearity of the density wave excited by the
perturber is shown to decrease as the wave travels out of the gap, slowing down
its nonlinear evolution and damping. Our results suggest that gap opening in
protoplanetary disks and gas clearing around SMBH binaries can be more
efficient than the existing theories predict. They pave the way for
self-consistent calculations of the gap structure and the orbital evolution of
the perturber using accurate prescription for the torque density behavior.

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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: math
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The categories of this paper are: patt-sol