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arXiv · 0811.0624

Spectral function and quasi-particle damping of interacting bosons in two dimensions

Andreas Sinner·Nils Hasselmann·Peter Kopietz
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Abstract

We employ the functional renormalization group to study dynamical properties of the two-dimensional Bose gas. Our approach is free of infrared divergences, which plague the usual diagrammatic approaches, and is consistent with the exact Nepomnyashchy identity, which states that the anomalous self-energy vanishes at zero frequency and momentum. We recover the correct infrared behavior of the propagators and present explicit results for the spectral line-shape, from which we extract the quasi-particle dispersion and damping.

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Andreas Sinner, Nils Hasselmann, Peter Kopietz. 2009-02-27. Spectral function and quasi-particle damping of interacting bosons in two dimensions. https://doi.org/10.1103/physrevlett.102.120601

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