Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal form-factor approach to dynamical correlation functions of
  integrable lattice models   We propose a method for calculating dynamical correlation functions at finite
temperature in integrable lattice models of Yang-Baxter type. The method is
based on an expansion of the correlation functions as a series over matrix
elements of a time-dependent quantum transfer matrix rather than the
Hamiltonian. In the infinite Trotter-number limit the matrix elements become
time independent and turn into the thermal form factors studied previously in
the context of static correlation functions. We make this explicit with the
example of the XXZ model. We show how the form factors can be summed utilizing
certain auxiliary functions solving finite sets of nonlinear integral
equations. The case of the XX model is worked out in more detail leading to a
novel form-factor series representation of the dynamical transverse two-point
function.

21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs