Résumé / Abstract Seminaire_GReCO

"Dynamics and Energy Budget of Cosmological 1st Order Phase Transitions"

J. M. No
Service Physique Théorique (DSM/SPhT), CEA-Saclay (Saclay, France)

A cosmological first order phase transition can lead to many interesting phenomena, such as electroweak baryogenesis or the production of a stochastic background of gravitational waves. The phase transition procees through the nucleation and subsequent expansion of bubbles, and the understanding of the dynamics of their expansion is very relevant for the study of these phenomena. In particular some quantities, like the bubble wall velocity or the energy efficiency coefficients (for converting the available free energy of the Higgs field into fluid bulk motion, thermal energy and gradient/kinetic energy of the Higgs field) play a key role. I will first review the hydrodynamic treatment used to describe the fluid motion once bubbles start growing, and obtain the energy conversion efficiency coefficients that allow the energy budget of the phase transition to be analyzed. Then I will comment on some recent developments on the process of bubble expansion in cosmological phase transitions, like the existence of continuosly accelerating (""runaway"") bubbles or the possible occurence of hydrodynamic obstructions, and explain how they modify the previous analysis.

lundi 7 février 2011 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

Page web du séminaire / Seminar's webpage