Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A Novel Approach in Constraining Electron Spectra in Blazar Jets: The
  Case of Markarian 421
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an