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

Gould, Oliver; Tenkanen, Tuomas V. I.

Abstract

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.

Citation

Gould, O., & Tenkanen, T. V. I. (2021). On the perturbative expansion at high temperature and implications for cosmological phase transitions. Journal of High Energy Physics, 2021(06), Article 69. https://doi.org/10.1007/JHEP06%282021%29069

• Journal Article Type: Article
• Acceptance Date: May 15, 2021
• Online Publication Date: Jun 9, 2021
• Publication Date: Jun 1, 2021
• Deposit Date: Sep 8, 2021
• Publicly Available Date: Sep 8, 2021
• Journal: Journal of High Energy Physics
• Electronic ISSN: 1029-8479
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 2021
• Issue: 06
• Article Number: 69
• DOI: https://doi.org/10.1007/JHEP06%282021%29069
• Keywords: Nuclear and High Energy Physics
• Public URL: https://nottingham-repository.worktribe.com/output/6187483
• Publisher URL: https://link.springer.com/article/10.1007%2FJHEP06%282021%29069
• Additional Information: Received: 12 April 2021; Accepted: 15 May 2021; First Online: 9 June 2021