Dark Energy Constraints from Baryon Acoustic Oscillations

August 2006 • 2006ApJ...647....1W

Authors • Wang, Yun

Abstract • Baryon acoustic oscillations (BAOs) in the galaxy power spectrum allow us to extract the scale of the comoving sound horizon at recombination, a cosmological standard ruler accurately determined by the cosmic microwave background anisotropy data. We examine various issues important in the use of BAOs to probe dark energy. We find that if we assume a flat universe and priors on Ω_m, Ω_mh², and Ω_bh² as expected from the Planck mission, the constraints on dark energy parameters (w₀, w') scale much less steeply with survey area than (area)^-1/2 for a given redshift range. The constraints on the dark energy density ρ_X(z), however, do scale roughly with (area)^-1/2 due to the strong correlation between H(z) and Ω_m (which reduces the effect of priors on Ω_m). Dark energy constraints from BAOs are very sensitive to the assumed linear scale of matter clustering and the redshift accuracy of the survey. For a BAO survey with 0.5<=z<=2, σ(R)=0.4 [corresponding to k_max(z=0)=0.086 h Mpc^-1], and σ_z/(1+z)=0.001, we find (σ_w0,σ_w^')=(0.115,0.183) and (0.069, 0.104) for survey areas of 1000 and 10,000 deg², respectively. We find that it is critical to minimize the bias in the scale estimates in order to derive reliable dark energy constraints. For a 1000 (10,000) deg² BAO survey, a 1 σ bias in lnH(z) leads to a 2 σ (3 σ) bias in w'. The bias in w' due to the same scale bias from lnD_A(z) is slightly smaller and opposite in sign. The results from this paper will be useful in assessing different proposed BAO surveys and guiding the design of optimal dark energy detection strategies.

Links

• PDF https://stacks.iop.org/0004-637X/647/1/pdf
• PREPRINT http://arxiv.org/abs/astro-ph/0601163
• ELECTR https://doi.org/10.1086%2F505384
• SPIRES http://inspirehep.net/search?p=find+eprint+astro-ph/0601163