Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photon Ring Symmetries in Simulated Linear Polarization Images of
  Messier 87*   The Event Horizon Telescope (EHT) recently released the first linearly
polarized images of the accretion flow around the supermassive black hole
Messier 87*, hereafter \m{}. The spiraling polarization pattern found in EHT
images favored magnetically arrested disks (MADs) as the explanation for the
EHT image. With next-generation improvements to very long baseline
interferometry (VLBI) on the horizon, understanding similar polarized features
in the highly lensed structure known as the "photon ring," where photons make
multiple half-orbits about the black hole before reaching the observer, will be
critical to analysis of future images. Recent work has indicated that this
image region may be depolarized relative to more direct emission. We expand
this observation by decomposing photon half-orbits in the EHT library of
simulated images of the \m{} accretion system and find that images of MAD
simulations show a relative depolarization of the photon ring attributable to
destructive interference of oppositely spiraling electric field vectors; this
antisymmetry, which arises purely from strong gravitational lensing, can
produce up to ${\sim}50\%$ depolarization in the photon ring region with
respect to the direct image. In systems that are not magnetically arrested and
with the exception of systems with high spin and ions and electrons of equal
temperature, we find that highly lensed indirect sub-images are almost
completely depolarized, causing a modest depolarization of the photon ring
region in the complete image. We predict that next-generation EHT observations
of \m{} polarization should jointly constrain the black hole spin and the
underlying emission and magnetic field geometry.

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The categories of this paper are: q-alg
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: math
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: cond-mat