2008/01/31 by Abraham Loeb, Stuart Wyithe · 1 citation
Physics and Astronomy · #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevlett.100.161301
published as Phys.Rev.Lett.100:161301,2008 · 4 pages, 3 figures, Accepted for publication in Physical Review Letters
arxiv created 2008/03/21 · arxiv updated 2009/12/01
Measurements of the 21cm line emission by residual cosmic hydrogen after reionization can be used to trace the power spectrum of density perturbations through a significant fraction of the observable volume of the Universe. We show that a dedicated 21cm observatory coule probe a number of independent modes that is two orders of magnitude larger than currently available, and enable a cosmic-variance limited detection of the signature of a neutrino mass ~0.05eV. The evolution of the linear growth factor with redshift could also constrain exotic theories of gravity or dark energy to an unprecedented precision.