Centre for Particle Theory Colloquia: Aeons Before the Big Bang?
17 November 2009 16:15 in CLC203 (with coffee ad biscuits in the same room at 15:45)
The cosmic microwave background (CMB) provides much of the
impressive evidence for an enormously hot and dense early stage of the
universe - referred to as the Big Bang - but was this singular event
actually the absolute beginning? Observations of the CMB are now very
detailed, but this very detail presents new puzzles, one of the most
blatant being an apparent paradox in relation to the Second Law of
thermodynamics. The hypothesis of inflationary cosmology has long been
argued to explain away some of these puzzles, but it does not resolve
some key issues, including that raised by the Second Law. In this
talk, I describe a quite different proposal, which posits a succession
of universe aeons prior to our own. The expansion of the universe
never reverses in this scheme, but the space-time geometry is
nevertheless made consistent through a fundamental role for conformal
geometry. Black-hole evaporation turns out to be central to the Second
Law. Some analysis of CMB data, obtained from the WMAP satellite
provides a tantalizing input to these issues.
Coffee and biscuits at 15:30 in CM 211 (Maths Coffee Room).