Progress of Theoretical Physics

On the Phonon-Phonon Interaction in a System of Bose Particles

Sigenobu Sunakawa, Yoshimatsu Yokoo, Hiroshi Nakatani

Published Jul 1, 1962• 7 citations

Abstract

The definite expression of the phonon-phonon interaction in a Bose system is derived up to the order of N-1 in terms of the density operator and its exact canonical conjugate which was introduced in the previous papers. We find some mathematical ambiguity in the course of calculation, and clarify the reason why the different results were obtained so far. The validity of our formalism is discussed from the physical point of view.

DOI: 10.1143/ptp.28.127

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