Full Program »
Can Typicality Arguments Dissolve Cosmology’s Flatness Problem?The flatness problem in cosmology draws attention to a surprising fine-tuning of the spatial geometry of our universe towards flatness. Several physicists, among them Hawking, Page, Coule, and Carroll, have argued against the probabilistic intuitions underlying such fine-tuning arguments in cosmology and instead propose that the canonical measure on the phase space of Friedman-Robertson-Walker spacetimes should be used to evaluate fine-tuning. They claim that flat spacetimes in this set are actually typical on this natural measure and that therefore the flatness problem is illusory. I argue that they misinterpret typicality in this phase space and, moreover, that no conclusion can be drawn at all about the flatness problem by using the canonical measure alone.
University of California San Diego