Speaker
Description
Phase transitions are violent and interesting phenomena that could have occurred in the early stages of the universe. Possible perturbative techniques to study these phenomena and predict their gravitational wave background can be used in the presence of a hierarchy of scales, leading to the construction of Effective Field Theories at finite temperature by integrating out the heavier scales. These EFTs are actually reliable when the dynamics are mainly encoded in the most relevant operators. I will then discuss the limits of such EFTs, showing how higher-dimensional operators affect the theoretical prediction of stronger transitions, including those detectable by LISA. These considerations impact the applicability of effective theory techniques, including their use in non-perturbative lattice studies.
