Attractive versus repulsive interactions in the Bose-Einstein condensation dynamics of relativistic field theories

• Verfasst von: Berges, Jürgen [VerfasserIn]
• Verfasst von: Boguslavski, Kirill [VerfasserIn]
• Verfasst von: Chatrchyan, Aleksandr [VerfasserIn]
• Verfasst von: Jaeckel, Joerg [VerfasserIn]
• Titel: Attractive versus repulsive interactions in the Bose-Einstein condensation dynamics of relativistic field theories
• Verf.angabe: J. Berges, K. Boguslavski, A. Chatrchyan, and J. Jaeckel
• E-Jahr: 2017
• Jahr: 30 October 2017
• Umfang: 20 S.
• Fussnoten: Gesehen am 09.11.2017
• Titel Quelle: Enthalten in: Physical review
• Ort Quelle: Woodbury, NY : Inst., 2016
• Jahr Quelle: 2017
• Band/Heft Quelle: 96(2017,7) Artikel-Nummer 076020, 20 Seiten
• ISSN Quelle: 2470-0029
• DOI: doi:10.1103/PhysRevD.96.076020
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1565169034

Abstract

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. For 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 (two-particle-irreducible) 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.