Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Current conservation and ratio rules in magnetic metals with Coulomb
  repulsion   From general considerations of spin-symmetry breaking associated with
(anti-)ferromagnetism in metallic systems with Coulomb repulsion, we obtain
interesting and simple all-order rules involving the ratios of the densities of
states. These are exact for ferromagnetism under reasonable conditions, and
nearly exact for anti-ferromagnetism. In the case of ferromagnetism, the
comparison with the available experimental and theoretical numbers yields
favourable results.

14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs