Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electron sound in metals   This paper is devoted to the investigation of electron sound -- oscillations
of the electron distribution function coupled with elastic deformation and
propagating with the Fermi velocity. The amplitude-phase relations
characterizing the behavior of the electron sound in Ga single crystals are
determined experimentally. A model problem of excitation of electron sound in a
compensated metal with equivalent bands is solved for a finite sample with
diffusive scattering of electrons at the interfaces. It was found that the
displacement amplitude of the receiving interface is two orders of magnitude
larger than the elastic amplitude of the wave due to electron pressure. It was
established that the changes occurring in the amplitude and phase of the
electron sound waves at a superconducting transition do not depend on the path
traversed by the wave, i.e. they refer only to the behavior of the
transformation coefficient.

19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol