Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the Lamb vector divergence, evolution of pressure fields and
  Navier-Stokes regularity
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas