Quasiparticle excitations in relativistic quantum field theory

Daniel Arteaga

doi:10.1016/j.aop.2008.12.002

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arXiv · 0801.4324

Quasiparticle excitations in relativistic quantum field theory

Daniel Arteaga

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Abstract

We analyze the particle-like excitations arising in relativistic field theories in states different than the vacuum. The basic properties characterizing the quasiparticle propagation are studied using two different complementary methods. First we introduce a frequency-based approach, wherein the quasiparticle properties are deduced from the spectral analysis of the two-point propagators. Second, we put forward a real-time approach, wherein the quantum state corresponding to the quasiparticle excitation is explicitly constructed, and the time-evolution is followed. Both methods lead to the same result: the energy and decay rate of the quasiparticles are determined by the real and imaginary parts of the retarded self-energy respectively. Both approaches are compared, on the one hand, with the standard field-theoretic analysis of particles in the vacuum and, on the other hand, with the mean-field-based techniques in general backgrounds.

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Daniel Arteaga. 2008-01-28. Quasiparticle excitations in relativistic quantum field theory. https://doi.org/10.1016/j.aop.2008.12.002

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