Dark energy and time-dependent string compactifications

by Paul Townsend (DAMTP Cambridge)

Wednesday 19 Oct 2022, 15:00 → 16:00 Europe/Rome

1/1-2 - Aula "C. Voci" (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

The standard interpretation of dark energy is as a cosmological constant.  This implies a late-time de Sitter universe, which presents difficulties for quantum gravity theories, string/M-theory in particular. This talk will review some of these difficulties, and some past and recent attempts to circumvent them via time-dependent compactifications of the 10 or 11 dimensional effective supergravity theories of string/M-theory; the main advantage appears to be the possibility of recurrent cosmic acceleration in which the universe cycles through several de Sitter phases before approaching a late-time decelerating solution.