BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Which universes does the no-boundary wave function favour? - Jean-
 Luc Lehners (MPI for Gravitational Physics\, Potsdam)
DTSTART:20240513T090000Z
DTEND:20240513T100000Z
UID:TALK212587@talks.cam.ac.uk
CONTACT:Thomas Colas
DESCRIPTION:I will provide an introduction to the no-boundary wave functio
 n\, and review its implementation in simple inflationary models. Earlier t
 reatments indicated that the no-boundary wave function would favour very s
 hort inflationary phases\, in strong tension with observations. Recent inv
 estigations have shown the need for a more careful definition\, especially
  with regards to the question of which metrics and field configurations sh
 ould be summed over in gravitational path integrals. This leads both to a 
 deeper understanding of gravitational path integrals\, and to the conseque
 nce that\, under certain circumstances\, long inflationary phases are requ
 ired. I will discuss the implications for observational predictions\, in p
 articular for the size of the universe\, and I will comment on the relatio
 n to string theory. 
LOCATION:CMS\, Pav. B\, MR9 (B0.09) 
END:VEVENT
END:VCALENDAR