Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Half-Quantum Vortices in Superfluid Helium   This is the manuscript version of the Physics ViewPoint article introducing
the paper "Observation of half-quantum vortices in topological superfluid
$^3$He", by S. Autti et al., which appeared in Physical Review Letters,
December 14, 2016.

10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga