Speaker
Description
Scale hierarchies are required to reliably describe the thermodynamics of cosmological first-order phase transitions using perturbation theory. At finite temperature, such a hierarchy is provided naturally. One can then use this hierarchy to construct a three-dimensional effective field theory (EFT) that systematically includes thermal resummations to all orders.
Using this EFT setup, I discuss completing the perturbative program for equilibrium thermodynamics of cosmological first-order phase transitions by determining the finite-temperature effective potential of gauge-Higgs theories at next-to-next-to-next-to-next-to-leading order (N4LO) [1,2]. This N4LO result is the last perturbative order before confinement renders electroweak gauge-Higgs theories non-perturbative at four-loops. In contrast with non-perturbative lattice results, the perturbative thermodynamic predictions show remarkable agreement. As a direct application for predictions of gravitational waves produced by a first-order transition, this computation provides the final fully perturbative results for the phase transition strength and speed of sound.
[1] A. Ekstedt, P. Schicho, and T. V. I. Tenkanen, DRalgo: A package for effective field theory approach for thermal phase transitions, Comput. Phys. Commun. 288, 108725 (2023), [2205.08815].
[2] A. Ekstedt, P. Schicho, and T. V. I. Tenkanen, Cosmological phase transitions at three loops: the final verdict on perturbation theory (2024), [2405.18349].
