Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Bethe-Salpeter equation in Minkowski space with cross-ladder kernel
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin