Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Cooling of Compact Stars   The cooling of a compact star depends very sensitively on the state of dense
matter at supranuclear densities, which essentially controls the neutrino
emission, as well as on the structure of the stellar outer layers which control
the photon emission. Open issues concern the hyperon population, the presence
of meson condensates, superfluidity and superconductivity, and the transition
of confined hadronic matter to quark matter. This paper describes these issues
and presents cooling calculations based on a broad collection of equations of
state for neutron star matter and strange matter. These results are tested
against the body of observed cooling data.

25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas