Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Size-structured populations: immigration, (bi)stability and the net
  growth rate
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci