Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bound states in monopoles: sources for UHECR ?   Bound states in monopoles are studied through a simplified, Witten-like
model. As the overall structure is determined in full details, it is shown in
particular that only those states having a vanishing angular momentum are
allowed; for those, the energy spectrum is derived numerically and an
approximation is set up that allows an easy description in terms of
wavefunctions, usefull for further applications. The monopoles are then
proposed as candidates of ultra high energy cosmic rays, an hypothesis that
should soon be testable through the Pierre Auger Observatory.

12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph