Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dissipative Cylindrical Collapse of a Charged Anisotropic Fluid in
  $f(R)$ Gravity   This paper is devoted to investigate the cylindrical collapse of an
anisotropic fluid in $f(R)$ gravity. For this purpose, the viscous charged
anisotropic fluid dissipating energy with heat flow and shear is assumed. We
use the perturbation scheme to develop the dynamical equations for the
variables that ultimately lead to the disturbance of the physical variables and
the Starobinksy like $f(R)$ model chosen. The evolution of the matter variables
is discussed with the help of these equations. It can be concluded that the
range of dynamic instabilities depends on the field strength, density
distribution, pressure and the curvature term of the $f(R)$ model. We find that
our results of Newtonian and post-Newtonian regimes reduce asymptotically to
general relativity solutions in the limiting case.

14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph