Attractive vs. repulsive interactions in the Bose-Einstein condensation dynamics of relativistic field theories
We study the impact of attractive self-interactions on the nonequilibrium dynamics of relativistic quantum fields with large occupancies at low momenta. Our primary focus is on Bose-Einstein condensation and nonthermal fixed points in such systems. As a model system we consider O(N)-symmetric scalar...
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| Main Authors: | , , , |
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| Format: | Article (Journal) Chapter/Article |
| Language: | English |
| Published: |
24 Jul 2017
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| In: |
Arxiv
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| Online Access: | Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1707.07696
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| Author Notes: | J. Berges, K. Boguslavski, A. Chatrchyan and J. Jaeckel |
| Summary: | We study the impact of attractive self-interactions on the nonequilibrium dynamics of relativistic quantum fields with large occupancies at low momenta. Our primary focus is on Bose-Einstein condensation and nonthermal fixed points in such systems. As a model system we consider O(N)-symmetric scalar field theories. We use classical-statistical real-time simulations, as well as a systematic 1/N expansion of the quantum (2PI) effective action to next-to-leading order. When the mean self-interactions are repulsive, condensation occurs as a consequence of a universal inverse particle cascade to the zero-momentum mode with self-similar scaling behavior. For attractive mean self-interactions the inverse cascade is absent and the particle annihilation rate is enhanced compared to the repulsive case, which counteracts the formation of coherent field configurations. For N >= 2, the presence of a nonvanishing conserved charge can suppress number changing processes and lead to the formation of stable localized charge clumps, i.e. Q-balls. |
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| Item Description: | Gesehen am 27.07.2017 |
| Physical Description: | Online Resource |