# Agenda

# Friday 14 December 2018

### Testing relativistic vacuum decay with cold atoms

#### Florent Michel

Vacuum decay is a prominent example of strongly nonlinear

effects in quantum field theory with potentially important

implications for cosmology, relating to phase transitions in the early

universe or the supposed metastability of the current Higgs vacuum.

Although a general theoretical description was laid out in the 80s by

Sidney Coleman and his collaborators, fundamental questions pertaining

to the back-reaction of true vacuum bubbles on space-time curvature

and their correlations remain so far unanswered, calling for different

approaches to the problem. In this talk, after a brief review of

Coleman’s theory emphasizing its genericness and limitations, I will

present a recently-proposed cold-atoms model in which some of these

ideas could be tested in laboratory experiments. I will discuss the

mathematical correspondence between the two problems and focus on how

a localized defect changes the decay rate, taking the example of a

vortex in a Bose-Einstein condensate and comparing with the effect of

a black hole in a relativistic theory.