Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Rayleigh-B\`enard convection in the generalized Oberbeck-Boussinesq
  system
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org