Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The generalized Lemaitre-Tolman-Bondi solutions with nonzero pressure in
  modeling the cosmological black holes   In this work we have obtained the set of new exact solutions of the Einstein
equations that generalize the known Lemaitre-Tolman-Bondi solution for the
certain case of nonzero pressure under zero spatial curvature. These solutions
are pretending to describe the black hole immersed in the nonstatic
cosmological background and give a possibility to investigate the problems
concerning the effects of the cosmological expansion in gravitationally bounded
systems. They may also be used as a seed models in the problem of structure
formation in the universe at the epoch of matter and radiation decoupling. It
was shown that each of the solutions obtained contains either the
Reissner-Nordstrom or the Schwarzschild black hole in the central region of the
space. It is demonstrated that the approach of the mass function use in solving
the Einstein equations allows clear physical interpretation of the resulting
solutions that is of much benefit to any their further application.

30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph