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CRC Press eBooks

Transport Phenomena

Leo P. Kadanoff, Gordon Baym

Published Mar 8, 2018• 0 citations
Publisher

Abstract

So far, we have studied many-body systems by considering the effect of adding or removing one or more particles. From the one-particle Green’s function G(1 − 1′) we were able to determine the energy spectrum and decay times of the single-particle excited states.
DOI
10.1201/9780429493218-6

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The static and dynamic properties of an isotropic quadrupolar system are studied by the method of double-time Green's functions. Using symmetrized equations of motion, a Dyson equation for the single-particle Green's function is obtained. The self-energy is expressed in terms of three-particle Green's functions, which are determined using an effective Hamiltonian, with the exact commutation relations approximated by quasiboson ones. A detailed expression for the lifetime of the elementary excitations is obtained.