Abstract
The properties of sound in a Fermi liquid are discussed for the case when the frequency of the wave is comparable with the collision frequency. We show that if the zero-sound velocity is very much greater than the Fermi velocity, as it is in liquid3He, the kinetic equation is of the same form as for the frequency-dependent conductivity of a normal Fermi liquid. By employing upper and lower bounds for the frequency-dependent conductivity obtained by Ah-Sam, Hojgaard Jensen, and Smith, we obtain bounds on the velocity and attenuation of sound. Other bounds, which are in many cases better than these, have also been found and employed. Both the velocity and attenuation are reduced compared with what one would expect on the basis of a simple interpolation formula consistent with the exact results for the zero-sound and first-sound regimes. For liquid3He the reductions in the attenuation are expected to be of the order of about3%.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
