Testing the copernican principle via cosmological observations

Abstract

Observations of distances to Type-Iasupernovae can be explained by cosmological models that include either a gigaparsec-scale void, or a cosmic flow, without the need for Dark Energy. Instead of invoking dark energy, theseinhomogeneous models instead violate the Copernican Principle.we show that current cosmological observations (Supernovae, Baryon Acoustic Oscillations and estimates of the Hubble parameters based on the age of the oldest stars) are not able to rule out inhomogeneous anti-Copernican models.The next generation of surveys for baryonic acoustic oscillationswill be sufficiently precise to either validatethe Copernican Principle or determine the existence of a local Gpc scale inhomogeneity.