Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Free energy of a charged oscillator in a magnetic field and coupled to a
  heat bath through the momentum variables
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas