Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The mass formula for quasi-black holes   A quasi-black hole, either non-extremal or extremal, can be broadly defined
as the limiting configuration of a body when its boundary approaches the body's
quasihorizon. We consider the mass contributions and the mass formula for a
static quasi-black hole. The analysis involves careful scrutiny of the surface
stresses when the limiting configuration is reached. It is shown that there
exists a strict correspondence between the mass formulas for quasi-black holes
and pure black holes. This perfect parallelism exists in spite of the
difference in derivation and meaning of the formulas in both cases. For
extremal quasi-black holes the finite surface stresses give zero contribution
to the total mass. This leads to a very special version of Abraham-Lorentz
electron in general relativity in which the total mass has pure electromagnetic
origin in spite of the presence of bare stresses.

14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph