Accuracy of cosmological parameters using the baryon acoustic scale

Thepsuriya, Kiattisak and Lewis, Antony (2015) Accuracy of cosmological parameters using the baryon acoustic scale. Journal of Cosmology and Astroparticle Physics, 2015 (01). 034-034. ISSN 1475-7516

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Percent-level measurements of the comoving baryon acoustic scale standard ruler can be used to break degeneracies in parameter constraints from the CMB alone. The sound horizon at the epoch of baryon drag is often used as a proxy for the scale of the peak in the matter density correlation function, and can conveniently be calculated quickly for different cosmological models. However, the measurements are not directly constraining this scale, but rather a measurement of the full correlation function, which depends on the detailed evolution through decoupling. We assess the level of reliability of parameter constraints based on a simple approximation of the acoustic scale compared to a more direct determination from the full numerical two-point correlation function. Using a five-parameter fitting technique similar to recent BAO data analyses, we find that for standard _CDM models and extensions with massive neutrinos and additional relativistic degrees of freedom, the approximation is at better than 0:15% for most parameter combinations varying over reasonable ranges.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy
Depositing User: Richard Chambers
Date Deposited: 22 Oct 2015 13:08
Last Modified: 05 Aug 2019 13:46

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