BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Seeded nucleation in the early Universe - Simone Blasi (DESY)
DTSTART:20260309T130000Z
DTEND:20260309T140000Z
UID:TALK242632@talks.cam.ac.uk
CONTACT:Gonzalo Villa
DESCRIPTION:Cosmological phase transitions are fascinating events taking p
 lace in the first instants of the Universe. First order transitions procee
 ding via the nucleation of bubbles are of particular interest as they can 
 lead to a strong departure from thermal equilibrium\, with important impli
 cations for the generation of the observed matter-antimatter asymmetry as 
 well as for the production of primordial gravitational waves. These proper
 ties strongly depend on the dynamics controlling bubble nucleation: in a h
 omogenous Universe\, critical bubbles formed out of thermal or quantum flu
 ctuations are expected to be spherical in shape\, with a nucleation probab
 ility that is the same everywhere. This picture\, however\, can dramatical
 ly change if the Universe contains impurities\, or seeds\, that can expone
 ntially enhance the nucleation rate in their vicinity. In this talk\, I wi
 ll discuss the general idea behind seeded phase transitions\, and provide 
 few natural examples where topological defects\, such as strings and domai
 n walls\, can play the role of impurities in the early Universe.
LOCATION:CMS\, Pav. B\, CTC Common Room (B1.19) [Potter Room]
END:VEVENT
END:VCALENDAR