Theory of degenerate Bose gas without anomalous averages

V. B. Bobrov; S. A. Trigger

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arXiv · 1203.1270

Theory of degenerate Bose gas without anomalous averages

V. B. Bobrov·S. A. Trigger

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Abstract

Theory of a weakly non-ideal Bose gas in the canonical ensemble is developed without assumption of the C-number representation of the creation and annihilation operators with zero momentum. It is shown that the pole of the "density-density" Green's function exactly coincides with the Bogolybov's phonon-roton spectrum of excitations. At the same time, a gap exists in the one-particle excitation spectrum . This gap is related to the density of particles in the "condensate".

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V. B. Bobrov, S. A. Trigger. 2012-03-06. Theory of degenerate Bose gas without anomalous averages. https://arxiv.org/abs/1203.1270

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