Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Phase gradient protection of stored spatially multimode perfect optical
  vortex beams in a diffused rubidium vapor
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin