Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analog of Anderson theorem for the polar phase of liquid 3He in nematic
  aerogel   It is shown that if impurities in superfluid 3He have form of infinitely long
non-magnetic strands, which are straight, parallel to each other and reflect
quasi-particles specularly, the temperature of transition of liquid 3He from
the normal into the polar phase coincides with that for the bulk liquid without
impurities. Magnetic scattering lowers transition temperature for the polar
phase in analogy with the conventional superconductors. These results are
discussed in connection with the recent experimental findings.

16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int