Can a Local Void mimic Dark Energy?

by Dr Alessio Notari (CERN)

Thursday 6 Dec 2007, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

It is now a known fact that if we happen to be living in the middle of a large underdense region, then cosmological observations will look like ``apparent acceleration'', even when any form of dark energy is absent. However the question is if the existence of such a Void is realistic. We discuss a ``Minimal Void'' scenario, i.e. a ``void'' with minimal underdensity contrast (of about $-0.4$) and radius ($\sim 200-250$ Mpc/$h$) that can, not only be consistent with the supernovae data, but also with the 3-yr WMAP data. We also discuss other observations such as Big Bang Nucleosynthesis, Baryon Acoustic Oscillations and local measurements of the Hubble parameter.