Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Microscopic calculations of spin polarized neutron matter at finite
  temperature   The properties of spin polarized neutron matter are studied both at zero and
finite temperature within the framework of the Brueckner--Hartree--Fock
formalism, using the Argonne v18 nucleon-nucleon interaction. The free energy,
energy and entropy per particle are calculated for several values of the spin
polarization, densities and temperatures together with the magnetic
susceptibility of the system. The results show no indication of a ferromagnetic
transition at any density and temperature.

2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg