Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Villani conjecture on smoothing effect of the homogeneous Boltzmann
  equation with measure initial datum
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci