Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Static and rotating electrically charged black holes in
  three-dimensional Brans-Dicke gravity theories   We obtain static and rotating electrically charged black holes of a
Einstein-Maxwell-Dilaton theory of the Brans-Dicke type in (2+1)-dimensions.
The theory is specified by three fields, the dilaton, the graviton and the
electromagnetic field, and two parameters, the cosmological constant and the
Brans-Dicke parameter. It contains eight different cases, of which one
distinguishes as special cases, string theory, general relativity and a theory
equivalent to four dimensional general relativity with one Killing vector. We
find the ADM mass, angular momentum, electric charge and dilaton charge and
compute the Hawking temperature of the solutions. Causal structure and geodesic
motion of null and timelike particles in the black hole geometries are studied
in detail.

6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex