Scientific Colloquium
March 28, 2008
ANTHONY
AGUIRRE
UNIVERSITY OF CALIFORNIA SANTA CRUZ
"The Inflationary Multiverse"
An early epoch of extremely rapid
expansion, 'inflation', is widely accepted as a key component of our
standard cosmological model, and has made nontrivial and
observationally-confirmed predictions. But it has a peculiar and
profound side effect: in generic inflation models, the inflationary
epoch creates not just one region comparable to our observable
universe, but also infinitely many more such regions, leading to a
vast, complex spacetime often called the 'inflationary
multiverse'. To make matters even more interesting, contemporary
work in string theory strongly suggest that at sub-string energy
scales, string theory leads to a complex 'effective theory' that would
both drive eternal inflation, but also give different (low energy
effective) physics and cosmological properties to different regions;
this would give great diversity to the multiverse. In this talk I
will give an overview of these developments, focusing on giving a
picture of the structure of the multiverse, and addressing the issue of
how tests or predictions of multiverse models might be made.