Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Construction of the steady state density matrix and quasilocal charges
  for the spin-1/2 XXZ chain with boundary magnetic fields
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph