Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective excitations and thermodynamics of disordered state: new
  insights into an old problem   Disorder has been long considered as a formidable foe of theoretical
physicists in their attempts to understand system's behavior. Here, we review
recently accumulated data and propose that from the point of view of
calculating thermodynamic properties, the problem of disorder may not be as
severe as has been hitherto assumed. We particularly emphasize that contrary to
the long-held view, collective excitations do not decay in disordered systems.
We subsequently discuss recent experimental, theoretical and modelling results
related to collective excitations in disordered media, and show how these
results pave the way to understanding thermodynamics of disordered systems:
glasses, liquids, supercritical fluids and spin glasses. An interesting insight
from the recent work is the realization that most important changes of
thermodynamic properties of the disordered system are governed only by its
fundamental length, the interatomic separation. We discuss how the proposed
theory relates to the previous approaches based on general many-body
statistical mechanics framework.

26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex