Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Possible black universes in a brane world   A black universe is a nonsingular black hole where, beyond the horizon, there
is an expanding, asymptotically isotropic universe. Such spherically symmetric
configurations have been recently found as solutions to the Einstein equations
with phantom scalar fields (with negative kinetic energy) as sources of
gravity. They have a Schwarzschild-like causal structure but a de Sitter
infinity instead of a singularity. It is attempted to obtain similar
configurations without phantoms, in the framework of an RS2 type brane world
scenario, considering the modified Einstein equations that describe gravity on
the brane. By building an explicit example, it is shown that black-universe
solutions can be obtained there in the presence of a scalar field with positive
kinetic energy and a nonzero potential.

34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex