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Abstract: The measurement of the scale of the baryon acoustic oscillations (BAO) in thegalaxy power spectrum as a function of redshift is a promising method toconstrain the equation-of-state parameter of the dark energy w. To measure thescale of the BAO precisely, a substantial volume of space must be surveyed. Wetest whether light-cone effects are important and whether the scaling relationsused to compensate for an incorrect reference cosmology are in this casesufficiently accurate. We investigate the degeneracies in the cosmologicalparameters and the benefits of using the two-dimensional anisotropic powerspectrum. Finally, we estimate the uncertainty with which w can be measured byproposed surveys at redshifts of about z=3 and z=1, respectively.In the simulated survey we find that light-cone effects are small and thatthe simple scaling relations used to correct for the cosmological distortionwork fairly well even for large survey volumes. The analysis of thetwo-dimensional anisotropic power spectra enables an independent determinationto be made of the apparent scale of the BAO, perpendicular and parallel to theline of sight. This is essential for two-parameter w-models, such as theredshift-dependent dark energy model w=w 0+(1-a)w a. Using Planck priors forthe matter and baryon density and Delta(H 0)=5% for the Hubble constant, weestimate that the BAO measurements of future surveys around z=3 and z=1 will beable to constrain, independently of other cosmological probes, a constant w to~ 12% and ~ 11% (68% c.l.), respectively.



Autor: Christian Wagner, Volker Müller, Matthias Steinmetz

Fuente: https://arxiv.org/







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