Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft Modes, Quantum Transport and Kinetic Entropy   The effects of the propagation of particles which have a finite life-time and
an according width in their mass spectrum are discussed in the context of
transport descriptions. In the first part the coupling of soft photon modes to
a source of charged particles is studied in a classical model which can be
solved completely in analytical terms. The solution corresponds to a
re-summation of certain field theory diagrams. The general properties of broad
resonances in dense finite temperature systems are discussed at the example of
the $\rho$-meson in hadronic matter. The second part addresses the problem of
transport descriptions which also account for the damping width of the
particles. The Kadanoff--Baym equation after gradient approximation together
with the $\Phi$-derivable method of Baym provides a self-consistent and
conserving scheme. Memory effects appearing in collision term diagrams of
higher order are discussed. We derive a generalized expression for the
nonequilibrium kinetic entropy flow, which includes corrections from
fluctuations and mass-width effects. In special cases an $H$-theorem is proved.
Memory effects in collision terms provide contributions to the kinetic entropy
flow that in the Fermi-liquid case recover the famous bosonic type $T^3 \ln T$
correction to the specific heat of liquid Helium-3.

7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con