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Résumé |
The possibility of observing a stochastic gravitational wave background
originating from a cosmological first-order phase transition elicits interest in
studying the transitions. Currently, a limiting factor in accurately determining
the gravitational wave spectrum from an underlying microphysical model is the
calculation of the nucleation rate. I will discuss recent work in which we have
proposed a new effective field theory (EFT) framework for determining the thermal
nucleation rate in high-temperature QFTs. Typical issues encountered in thermal
nucleation calculations (double counting fluctuations, stray imaginary parts and
diverging derivative expansions) arise due to an inconsistent treatment of
nucleating bubbles. Using the EFT framework, we are able to create an effective
description for the length scale of the nucleating bubbles and hence treat the
nucleating bubbles consistently, resolving the aforementioned issues. In addition,
the framework provides a clear physical picture of the process by making a
connection to classical nucleation theory by Langer. |
