Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonextreme black holes near the extreme state and acceleration horizons:
  thermodynamics and quantum-corrected geometry   We consider the class of metrics that can be obtained from those of
nonextreme black holes by limiting transitions to the extreme state such that
the near-horizon geometry expands into a whole manifold. These metrics include,
in particular, the Rindler and Bertotti - Robinson spacetimes. The general
formula for the entropy of massless radiation valid either for black-hole or
for acceleration horizons is derived. It is argued that, as a black hole
horizon in the limit under consideration turns into an acceleration one, the
thermodynamic entropy $S_{q}$ of quantum radiation is due to the Unruh effect
entirely and $S_{q}=0$ exactly. The contribution to the quasilocal energy from
a given curved spacetime is equal to zero and the only nonvanishing term stems
from a reference metric. In the variation procedure necessary for the
derivation of the general first law, the metric on a horizon surface changes
along with the boundary one, and the account for gravitational and matter
stresses is an essential ingredient of the first law. This law confirms the
property $S_{q}=0$. The quantum-corrected geometry of the Bertotti - Robinson
spacetime is found and it is argued that backreaction of quantum fields mimics
the effect of the cosmological constant $\Lambda_{eff\text{}}$ and can
drastically change the character of spacetime depending on the sign of $\Lambda
_{eff}$ --- for instance, turn $AdS_{2}\times S_{2}$ into $dS_{2}\times S_{2}$
or $Rindler_{2}\times S_{2}$. Two latter solutions can be thought of as the
quantum versions of the cold and ultracold limits of the Reissner-Nordstrom-de
Sitter metric.

36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con