Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ising field theory in a magnetic field: analytic properties of the free
  energy   We study the analytic properties of the scaling function associated with the
2D Ising model free energy in the critical domain $T \to T_c$, $H \to 0$. The
analysis is based on numerical data obtained through the Truncated Free Fermion
Space Approach. We determine the discontinuities across the Yang-Lee and Langer
branch cuts. We confirm the standard analyticity assumptions and propose
"extended analyticity"; roughly speaking, the latter states that the Yang-Lee
branching point is the nearest singularity under Langer's branch cut. We
support the extended analyticity by evaluating numerically the associated
"extended dispersion relation".

22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
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The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga