Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonsingular black holes, wormholes, and de Sitter cores from anisotropic
  fluids   We study Born-Infeld gravity coupled to an anisotropic fluid in a static,
spherically symmetric background. The free function characterizing the fluid is
selected on the following grounds: i) recovery of the Reissner-Nordstr\"om
solution of GR at large distances, ii) fulfillment of classical energy
conditions and iii) inclusion of models of nonlinear electrodynamics as
particular examples. Four branches of solutions are obtained, depending on the
signs of two parameters on the gravity and matter sectors. On each branch, we
discuss in detail the modifications on the innermost region of the
corresponding solutions, which provides a plethora of configurations, including
nonsingular black holes and naked objects, wormholes and de Sitter cores. The
regular character of these configurations is discussed according to the
completeness of geodesics and the behaviour of curvature scalars.

11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph