Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On astrophysical solution to ultra high energy cosmic rays
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom