Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Zero-mode analysis of quantum statistical physics   We present a unified formulation for quantum statistical physics based on the
representation of the density matrix as a functional integral. We identify the
stochastic variable of the effective statistical theory that we derive as a
boundary configuration and a zero mode relevant to the discussion of infrared
physics. We illustrate our formulation by computing the partition function of
an interacting one-dimensional quantum mechanical system at finite temperature
from the path-integral representation for the density matrix. The method of
calculation provides an alternative to the usual sum over periodic
trajectories: it sums over paths with coincident endpoints, and includes
non-vanishing boundary terms. An appropriately modified expansion into
Matsubara modes provides a natural separation of the zero-mode physics. This
feature may be useful in the treatment of infrared divergences that plague the
perturbative approach in thermal field theory.

5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph