Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Entanglement entropy in quantum spin chains with broken reflection
  symmetry
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th