Time drift of cosmological redshifts as a test of the Copernican principle.
We present the time drift of the cosmological redshift in a general spherically symmetric spacetime. We demonstrate that its observation would allow us to test the Copernican principle and so determine if our Universe is radially inhomogeneous, an important issue in our understanding of dark energy. In particular, when combined with distance data, this extra observable allows one to fully reconstruct the geometry of a spacetime describing a spherically symmetric underdense region around us, purely from background observations.
Institut d'Astrophysique de Paris, Université Pierre and Marie Curie-Paris VI, CNRS-UMR 7095, Paris, France. uzan@iap.fr
Jean-Philippe
JP
Uzan
Chris
C
Clarkson
George F R
GF
Ellis