IAU01133
Presentation type requested: ORAL
MEASURING DARK ENERGY WITH THE RULER OF ACOUSTIC PEAKS
Chris Blake
University of New South Wales
A precision measurement of the galaxy power spectrum on scales larger than 30 Mpc would reveal the acoustic oscillations imprinted at recombination. The positions of these peaks in Fourier space, fixed by fundamental linear physics in the early Universe and mapped accurately by CMB measurements, can be used as a "standard cosmological ruler" to facilitate accurate measurement of the dark energy that dominates in the late Universe. Such power spectrum measurements must be performed at high redshift, where the linear regime of galaxy clustering extends to small scales and the pattern of acoustic peaks is preserved. We have quantified the ability of future large-scale galaxy redshift surveys with mean redshifts z=1 and z=3 to delineate the baryonic peaks, and have derived corresponding constraints on the parameter w describing the equation of state of dark energy. A survey of a million galaxies at z=1, covering three times the Sloan volume, can produce a measurement with accuracy 0.1 in w. This method of measuring dark energy powerfully complements other probes such as Type Ia supernovae, suffering from very different (and arguably less serious) systematic uncertainties. Moreover, the new generation of wide-field multi-object spectographs on large telescopes makes such a survey very feasible.
Glazebrook Karl
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