
JOINT PARTICLE SEMINAR
Date: Wednesday,
27 October 2004
Time:
3:00 p.m.
Place: 4135 Frederick Reines Hall
Speaker:
Dr. Michael Graesser, Caltech
Title:Anthropic Distribution for Cosmological
Constant and Primoridal Density Perturbations
Abstract:
The anthropic principle has been proposed as an explanation for the
observed
value of the cosmological constant. Here we revisit this proposal by
allowing for variation between universes in the amplitude of the
scale-invariant primordial cosmological density perturbations. We
derive a
priori probability distributions for this amplitude from toy
inflationary
models in which the parameter of the inflaton potential is smoothly
distributed over possible universes. We find that for such probability
distributions, the likelihood that we live in a typical,
anthropically-allowed universe is generally quite small.
Host: A. Rajaraman