Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A $Gaia$ Data Release 2 catalogue of white dwarfs and a comparison with
  SDSS
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int