Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comparison of different forms for the "spin" and "orbital" components of
  the angular momentum of light   We compare three attempts that have been made to decompose the angular
momentum of the electromagnetic field into components of an "orbital" and
"spin" nature. All three expressions are different and it appears, on the basis
of classical electrodynamics, that there is no preferred way of decomposing the
angular momentum of the electromagnetic field into orbital and spin components,
even in an inertial frame.

32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th