Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Variable Density Model for the Rayleigh-Taylor Instability and its
  transformation to the diffusive, inhomogeneous, incompressible Navier-Stokes
  equations
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat