Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A minimal model for excitons within time-dependent density-functional
  theory
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics