HET Seminar Dec 8th: Rashmish Mishra

Rashmish Mishra: Holographic Phase Transitions in the early Universe

Strongly coupled confining theories are well-motivated in many BSM frameworks. The early universe cosmological history of these theories provides possibilities for observable signals. These theories undergo confinement deconfinement phase transition in the early universe, which can result in gravitational wave signals, observable in upcoming experiments. Using AdS/CFT, these theories have been studied in the Randall-Sundrum framework, and various quantitative aspects of the phase transition have been calculated. In the models that have been considered, the rate of transition from the hot phase to the confined phase is very small and leads to a period of supercooling. This enhances the gravitational wave signal, but presents a tension between a low confinement scale and fitting to the standard picture of BBN. In this talk, I will revisit these features and argue that some of the issues are specific to the simplified models that have been studied. I will present two modifications that are expected on general grounds and argue that both of them enhance the rate. I will also present the effect on the resulting phenomenology. The talk will be based on 2309.10090 and an ongoing work.