Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Best Approximation to a Reversible Process in Black-Hole Physics and the
  Area Spectrum of Spherical Black Holes   The assimilation of a quantum (finite size) particle by a
Reissner-Nordstr\"om black hole inevitably involves an increase in the
black-hole surface area. It is shown that this increase can be minimized if one
considers the capture of the lightest charged particle in nature. The
unavoidable area increase is attributed to two physical reasons: the Heisenberg
quantum uncertainty principle and a Schwinger-type charge emission (vacuum
polarization). The fundamental lower bound on the area increase is $4 \hbar$,
which is smaller than the value given by Bekenstein for neutral particles.
Thus, this process is a better approximation to a reversible process in
black-hole physics. The universality of the minimal area increase is a further
evidence in favor of a uniformly spaced area spectrum for spherical quantum
black holes. Moreover, this universal value is in excellent agreement with the
area spacing predicted by Mukhanov and Bekenstein and independently by Hod.

2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int