Speaker
Description
Phase transitions are violent and fascinating phenomena that may have occurred in the early Universe. When a hierarchy of scales is present, they can be studied using finite-temperature Effective Field Theories, obtained by integrating out the heavier degrees of freedom. Such EFTs provide a reliable description as long as the dynamics are dominated by the most relevant operators. In this talk, I will discuss the limitations of this approach, showing how and when higher-dimensional operators can significantly affect the prediction of strong first-order phase transitions, including those potentially detectable by LISA. I will then discuss the validity of these techniques in the context of the widely studied scenario of supercooled phase transitions.