Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physically valid black-hole interior models   New, simple models of ``black hole interiors'', namely spherically symmetric
solutions of the Einstein field equations in matter matching the Schwarzschild
vacuum at spacelike hypersurfaces ``R<2M'' are constructed. The models satisfy
the weak energy condition and their matter content is specified by an equation
of state of the elastic type.

22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex