Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Neutrino Emissivity of Strange Stars with Ultra Strong Magnetic
  Field   The effect of a strong magnetic field on the dominant neutrino emissivity in
strange stars is investigated. In ultra strong magnetic field, there exists an
enhanced neutrino emission because the charged particles are confined to the
lowest Landau level. The results show that the neutrino emissivity is
proportional to $T^5$ instead of conventional $T^6$, which implies more rapid
cooling behavior in magnetars than usual stars

17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
2
The categories of this paper are: math