Attractive vs. repulsive interactions in the Bose-Einstein condensation dynamics of relativistic field theories
| Autor: | Berges, J., Boguslavski, K., Chatrchyan, A., Jaeckel, J. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 96, 076020 (2017) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.96.076020 |
| Popis: | 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. Comment: 30 pages, 8 figures, minor revision, published version |
| Databáze: | arXiv |
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