Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Photospheric Magnetic Free Energy Density of Solar Active Regions
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat