Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Classifications of Twin Star Solutions for a Constant Speed of Sound
  Parameterized Equation of State   We explore the possible mass radius relation of compact stars for the
equation of states with a first order phase transition. The low density matter
is described by a nuclear matter equation of state resulting from fits to
nuclear properties. A constant speed of sound parametrization is used to
describe the high density matter phase with the speed of sound $c_s^2=1$.
  A classification scheme of four distinct categories including twin star
solutions, i. e. solutions with the same mass but differing radii, is found
which are compatible with the $M \ge 2M_\odot$ pulsar mass constraint.
  We show the dependence of the mass and radius differences on the transition
parameters and delineate that higher twin star masses are more likely to be
accompanied by large radius differences. These massive twin stars are generated
by high values of the discontinuity in the energy density and the lowest
possible values of the transition pressure that still result in masses of $M
\geq 2M_\odot$ at the maximum of the hadronic branch.

23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph