Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Four-dimensional black holes with scalar hair in nonlinear
  electrodynamics   We consider a gravitating system consisting of a scalar field minimally
coupled to gravity with a self-interacting potential and a U(1) nonlinear
electromagnetic field. Solving analytically and numerically the coupled system
for both power-law and Born-Infeld type electrodynamics, we find charged hairy
black hole solutions. Then, we study the thermodynamics of these solutions and
we find that at a low temperature the topological charged black hole with
scalar hair is thermodynamically preferred, whereas the topological charged
black hole without scalar hair is thermodynamically preferred at a high
temperature for power-law electrodynamics. Interestingly enough, these phase
transitions occur at a fixed critical temperature and do not depend on the
exponent $p$ of the nonlinearity electrodynamics.

8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
18
The categories of this paper are: econ
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas