skip to main content

This content will become publicly available on November 5, 2016

Title: Nonequilibrium fixed points in longitudinally expanding scalar theories: Infrared cascade, Bose condensation and a challenge for kinetic theory

In [Phys. Rev. Lett. 114, 061601 (2015)], we reported on a new universality class for longitudinally expanding systems, encompassing strongly correlated non-Abelian plasmas and N-component self-interacting scalar field theories. Using classical-statistical methods, we showed that these systems share the same self-similar scaling properties for a wide range of momenta in a limit where particles are weakly coupled but their occupancy is high. Here we significantly expand on our previous work and delineate two further self-similar regimes. One of these occurs in the deep infrared (IR) regime of very high occupancies, where the nonequilibrium dynamics leads to the formation of a Bose-Einstein condensate. The universal IR scaling exponents and the spectral index characterizing the isotropic IR distributions are described by an effective theory derived from a systematic large-N expansion at next-to-leading order. Remarkably, this effective theory can be cast as a vertex-resummed kinetic theory. The other novel self-similar regime occurs close to the hard physical scale of the theory, and sets in only at later times. In this study, we argue that the important role of the infrared dynamics ensures that key features of our results for scalar and gauge theories cannot be reproduced consistently in conventional kinetic theory frameworks.
 [1] ;  [2] ;  [3] ;  [2]
  1. Univ. Heidelberg, Heidelberg (Germany); ExtreMe Matter Institute (EMMI), GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. Univ. Heidelberg, Heidelberg (Germany)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1550-7998; PRVDAQ; R&D Project: 08870; KB0301020
Grant/Contract Number:
SC00112704; SC0012704; AC02-05CH11231
Accepted Manuscript
Journal Name:
Physical Review. D, Particles, Fields, Gravitation and Cosmology
Additional Journal Information:
Journal Volume: 92; Journal Issue: 9; Journal ID: ISSN 1550-7998
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States