Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evaporating black holes have leaky horizons or exotic atmospheres   Classically, black holes are compact objects with perfect semi-permeable
horizons: Anything may enter, nothing may leave. We consider an axiomatic
approach that applies to any black hole type, including arbitrarily
near-extremal black holes, that can unitarily evaporate away completely by any
mechanism. We show that a quantum black hole must either have a leaky horizon
(allowing quantum information out), or it must look very different from its
classical counterpart having an external neighborhood consisting of exotic
matter with super-ordinary entropic content (such as an `atmosphere' of
microscopic black holes).

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The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin
33
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: econ
4
The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga