Do stochastic inhomogeneities affect dark-energy precision measurements?
Abstract
The effect of a stochastic background of cosmological perturbations on the luminosity-redshift relation is computed to second order through a recently proposed covariant and gauge-invariant light-cone averaging procedure. The resulting expressions are free from both ultraviolet and infrared divergences, implying that such perturbations cannot mimic a sizable fraction of dark energy. Different averages are estimated and depend on the particular function of the luminosity distance being averaged. The energy flux, being minimally affected by perturbations at large z, is proposed as the best choice for precision estimates of dark-energy parameters. Nonetheless, its irreducible (stochastic) variance induces statistical errors on \Omega_{\Lambda}(z) typically lying in the few-percent range.
Keywords
Cite
@article{arxiv.1207.1286,
title = {Do stochastic inhomogeneities affect dark-energy precision measurements?},
author = {Ido Ben-Dayan and Maurizio Gasperini and Giovanni Marozzi and Fabien Nugier and Gabriele Veneziano},
journal= {arXiv preprint arXiv:1207.1286},
year = {2013}
}
Comments
5 pages, 3 figures. Comments and references added. Typos corrected. Version accepted for publication in Phys. Rev. Lett