The Cosmic Horizon
Fulvio Melia
Arizona
October 5, 2009, 4PM, Steward N210
The backbone of theoretical cosmology is the Friedmann-Robertson-Walker
(FRW) metric. But not since the 1920's has any serious attempt been made
to better understand its implications within the context of general
relativity. Now, with the potential of unprecedented clarity offered by
the most recent observations, e.g., with WMAP, Hubble, and Type Ia supernovae,
we here discuss several hitherto unrecognized properties of the FRW spacetime,
and with them demonstrate that though somewhat successful, the Lambda-CDM
(standard) model of cosmology does not appear to be fully consistent with the
data. In particular, dark energy cannot be a cosmological constant, but it
may be something that scales with the matter density, in a type of model
sometimes referred to as a "scaling solution."
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