I.F.T.

Almuerzo-Seminario

(Lunch seminar)

January 26th 1999, 14:00 p.m.

Stochastic Semiclassical Gravity

Enric Verdager

U. Barcelona

A Langevin type of equation is proposed as a consistent dynamical equation for a perturbative correction to semiclassical gravity. The equation accounts for the lowest order quantum fluctuations of the stress-energy tensor of matter fields. A semiclassical cosmological model with a cosmological constant is considered in which the back- reaction of the matter fields is able to drive the cosmological scale factor over the classical barrier into a de Sitter phase. This model is compared with the "tunneling from nothing" model in quantum cosmology.

The almuerzo-seminario is intended to be an informal seminar and an open forum for discussion.

You are wellcome to bring your own bocata (sandwich), or coffee or tea.

Where: Modulo C-XVI, 3rd floor, Facultad de Ciencias U.A.M., C.U. Cantoblanco, 28049-Madrid