Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The asymptotic speed of reaction fronts in active reaction-diffusion
  systems
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph