Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Strained BiFeO$_{3}$ perovskite structure for enhanced photovoltaic
  effect
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga