Oscillating scalar dissipating in a medium

0554711 - FZÚ 2022 RIV US eng J - Journal Article
Ai, W.Y. - Drewes, M. - Glavan, Dražen - Hajer, J.
Oscillating scalar dissipating in a medium.
Journal of High Energy Physics. Roč. 2021, č. 11 (2021), č. článku 160. ISSN 1029-8479. E-ISSN 1029-8479
R&D Projects: GA ČR(CZ) GA20-28525S
Institutional support: RVO:68378271
Keywords : quantum dissipative systems * thermal field theory * cosmology of theories beyond the SM
OECD category: Particles and field physics
Impact factor: 6.376, year: 2021
Method of publishing: Open access

We study how oscillations of a scalar field condensate are damped due to dissipative effects in a thermal medium. Our starting point is a non-linear and non-local condensate equation of motion descending from a 2PI-resummed effective action derived in the Schwinger-Keldysh formalism appropriate for non-equilibrium quantum field theory. We solve this non-local equation by means of multiple-scale perturbation theory appropriate for time-dependent systems, obtaining approximate analytic solutions valid for very long times. The non-linear effects lead to power-law damping of oscillations, that at late times transition to exponentially damped ones characteristic for linear systems.
Permanent Link: http://hdl.handle.net/11104/0329373