Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Proton spin: a topological invariant   Proton spin problem is given a new perspective with the proposition that spin
is a topological invariant represented by a de Rham 3-period. The idea is
developed generalizing Finkelstein-Rubinstein theory for Skyrmions/kinks to
topological defects, and using nonabelian de Rham theorems. Two kinds of de
Rham theorems are discussed applicable to matrix valued differential forms, and
traces. Physical and mathematical interpretations of de Rham periods are
presented. It is suggested that Wilson lines and loop operators probe the local
properties of the topology, and spin as a topological invariant in pDIS
measurements could appear with any value from 0 to $\frac{\hbar}{2}$, i. e.
proton spin decomposition has no meaning in this approach.

36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci