Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin polarized neutron matter within the Dirac-Brueckner-Hartree-Fock
  approach   The relation between energy and density (known as the nuclear equation of
state) plays a major role in a variety of nuclear and astrophysical systems.
Spin and isospin asymmetries can have a dramatic impact on the equation of
state and possibly alter its stability conditions. An example is the possible
manifestation of ferromagnetic instabilities, which would indicate the
existence, at a certain density, of a spin-polarized state with lower energy
than the unpolarized one. This issue is being discussed extensively in the
literature and the conclusions are presently very model dependent. We will
report and discuss our recent progress in the study of spin-polarized neutron
matter. The approach we take is microscopic and relativistic. The calculated
neutron matter properties are derived from realistic nucleon-nucleon
interactions. This makes it possible to understand the nature of the EOS
properties in terms of specific features of the nuclear force model.

23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom