Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sound modes broadening in quasicrystals   We propose a simple phenomenological model to analyze vibrational
characteristics of quasicrystals (QCs). The interpretation of the obtained
recently data is based on the existence of almost dispersionless optical modes
most probably related to the specific clusters which constitute the
characteristic building blocks of any QC structure. We generalize to QCs the
well - known Akhiezer mechanism, which in our case is related to a ''long
wave'' disturbance of the quasicrystalline optical modes by the propagating
sound modes. At higher wave vectors strong hybridization of acoustic and
optical modes takes place, and it leads to a more steep broadening dependence
on wave vectors, and besides the excitation can no longer be described as a
single acoustic mode with a well defined wave vector.

29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn