Natural Quintessence and the Braneworld Cliff Burgess (cliff@physics.mcgill.ca
) Abstract Current cosmological
measurements tell us that the universe contains 5% baryons, 25% dark matter
and 70% dark energy. The nature of the dark matter and the dark energy
is completely unknown, apart from the fact that they satisfy different
equations of states. This talk briefly summarizes the difficulties which
are encountered in explaining the dark energy. The focus is on naturalness
issues, which I argue provide very strong restrictions on the kinds of
cosmologies which can be considered. |