Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bondi-type accretion in the Reissner-Nordstr\"om-(anti-)de Sitter
  spacetime   In this paper I study stationary, spherically symmetric accretion of fluids
onto a charged black hole in the presence of the cosmological constant. For
some isothermal equations of state it is possible to obtain analytic solutions.
In the case of a radiation fluid I point out a connection between locations of
the horizons and the sonic (critical) points. In specific cases the solutions
form closed, binoculars-like trajectories in a phase diagram of the velocity
vs. radius.

2
The categories of this paper are: math
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con