Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Mode structure and orbital angular momentum of spatiotemporal optical
  vortex (STOV) pulses
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th