Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fermions and Correlations in the Two-Dimensional Ising Model   The anticommuting analysis with Grassmann variables is applied to the
two-dimensional Ising model in statistical mechanics. The discussion includes
the transformation of the partition function into a Gaussian fermionic
integral, the momentum-space representation and the spin-fermion correspondence
at the level of the correlation functions.

19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas