Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particles and strings in a (2+1)-D integrable quantum model   We give a review of some recent work on generalization of the Bethe ansatz in
the case of $2+1$-dimensional models of quantum field theory. As such a model,
we consider one associated with the tetrahedron equation, i.e. the
$2+1$-dimensional generalization of the famous Yang--Baxter equation. We
construct some eigenstates of the transfer matrix of that model. There arise,
together with states composed of point-like particles analogous to those in the
usual $1+1$-dimensional Bethe ansatz, new string-like states and
string-particle hybrids.

28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex