Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Sensitivity of vortex pairing and mixing to initial perturbations in
  stratified shear flows
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin