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arXiv · 1208.4845

Model Independent Early Expansion History and Dark Energy

Johan Samsing·Eric V. Linder·Tristan L. Smith
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Abstract

We examine model independent constraints on the high redshift and prerecombination expansion history from cosmic microwave background observations, using a combination of principal component analysis and other techniques. This can be translated to model independent limits on early dark energy and the number of relativistic species $N_{\rm eff}$. Models such as scaling (Doran-Robbers), dark radiation ($ΔN_{\rm eff}$), and barotropic aether fall into distinct regions of eigenspace and can be easily distinguished from each other. Incoming CMB data will map the expansion history from $z=0$--$10^5$, achieving subpercent precision around recombination, and enable determination of the amount of early dark energy and valuable guidance to its nature.

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Johan Samsing, Eric V. Linder, Tristan L. Smith. 2012-08-23. Model Independent Early Expansion History and Dark Energy. https://doi.org/10.1103/physrevd.86.123504

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