On the perturbative expansion at high temperature and implications for cosmological phase transitions

Journal of High Energy Physics

Tuomas V. I. Tenkanen¹  Oliver Gould² 

[1] Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91, Stockholm, Sweden;Tsung Dao Lee Institute/Shanghai Jiao Tong University, 200240, Shanghai, China;Shanghai Key Laboratory for Particle Physics and Cosmology, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Jiao Tong University, 200240, Shanghai, China;School of Physics and Astronomy, University of Nottingham, NG7 2RD, Nottingham, U.K.;

关键词: Cosmology of Theories beyond the SM;    Renormalization Group;    Resummation;    Thermal Field Theory;   

DOI  :  10.1007/JHEP06(2021)069

来源: Springer

【 摘 要 】

We revisit the perturbative expansion at high temperature and investigate its convergence by inspecting the renormalisation scale dependence of the effective potential. Although at zero temperature the renormalisation group improved effective potential is scale independent at one-loop, we show how this breaks down at high temperature, due to the misalignment of loop and coupling expansions. Following this, we show how one can recover renormalisation scale independence at high temperature, and that it requires computations at two-loop order. We demonstrate how this resolves some of the huge theoretical uncertainties in the gravitational wave signal of first-order phase transitions, though uncertainties remain stemming from the computation of the bubble nucleation rate.

【 授权许可】

CC BY