Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Wigner function for twisted photons   A comprehensive theory of the Weyl-Wigner formalism for the canonical pair
angle-angular momentum is presented, with special emphasis in the implications
of rotational periodicity and angular-momentum discreteness.

22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph