Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Spin-gap phase in the extended t-J chain
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org