Probing dark energy using baryonic oscillations in the galaxy power spectrum as a cosmological ruler
Abstract
Description
We show that the baryonic oscillations expected in the galaxy power spectrum may be used as a "standard cosmological ruler'' to facilitate accurate measurement of the cosmological equation of state. Our approach involves a straight-forward measurement of the oscillation "wavelength'' in Fourier space, which is fixed by fundamental linear physics in the early Universe and hence is highly model-independent. We quantify the ability of future large-scale galaxy redshift surveys with mean redshifts z~1 and z~3 to delineate the baryonic peaks in the power spectrum, and derive corresponding constraints on the parameter w describing the equation of state of the dark energy. For example, a survey of three times the Sloan volume at z ~ 1 can produce a measurement with accuracy dw ~ 0.1. We suggest that this method of measuring the dark energy powerfully complements other probes such as Type Ia supernovae, and suffers from a different (and arguably less serious) set of systematic uncertainties.
Submitted to Astrophysical Journal, 11 pages, 8 figures
Submitted to Astrophysical Journal, 11 pages, 8 figures