Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Continuous-time random-walk model for anomalous diffusion in expanding
  media
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat