Cosmological phase transition: Robust thermal resummation

by Dr Philipp Schicho (University of Helsinki)

Thursday 13 May 2021, 16:00 → 17:30 Asia/Seoul

Title: Cosmological phase transition: Robust thermal resummation

Speaker: Dr Philipp Schicho (University of Helsinki)

Abstract: 

Thermal field theories exhibit a rigorous scale hierarchy and their bosonic sector is rendered non-perturbative in the infrared.  Hence, to reliably describe the thermodynamics of the electroweak phase transition both perturbative and non-perturbative methods are needed.  At the intersection between these methods, one can construct a 3-dimensional effective theory that has thermal resummations systematically built in to all orders.

I apply computer algebraic multi-loop tools of perturbation theory for finite-temperature theories to determine this dimensionally reduced theory.  Therefrom, I demonstrate how to calculate the effective potential to describe cosmological first-order phase transitions in Beyond the Standard Model theories with extended Higgs sectors.  The theoretical uncertainties for such transitions are contrasted with other approaches to resummation.

Slides

Video