Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black hole quantum atmosphere for freely falling observers   We analyze Hawking radiation as perceived by a freely-falling observer and
try to draw an inference about the region of origin of the Hawking quanta. To
do so, first we calculate the energy density from the stress energy tensor, as
perceived by a freely-falling observer. Then we compare this with the energy
density computed from an effective temperature functional which depends on the
state of the observer. The two ways of computing these quantities show a
mismatch at the light ring outside the black hole horizon. To better understand
this ambiguity, we show that even taking into account the (minor) breakdown of
the adiabatic evolution of the temperature functional which has a peak in the
same region of the mismatch, is not enough to remove it. We argue that the
appearance of this discrepancy can be traced back to the process of particle
creation by showing how the Wentzel--Kramers--Brillouin approximation for the
field modes breaks down between the light ring at $3M$ and $4M$, with a peak at
$r=3.3M$ exactly where the energy density mismatch is maximized. We hence
conclude that these facts strongly support a scenario where the Hawking flux
does originate from a "quantum atmosphere" located well outside the black hole
horizon.

35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org