Time drift of cosmological redshifts and its variance

Abstract

The contribution of cosmological perturbations to the time drift of the cosmological redshift is derived. It is shown that the dominant correction arises from the local acceleration of both the emitter and the observer. The amplitude of this effect is estimated to be of the order of 1% of the drift signal at z=2-4, but can easily be lowered down to 0.1% by using many absorption lines and quasars.

6 pages, 2 figures. Fig. 1 modified. Accepted for publication in PRD