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arXiv · 1505.04443

Reconstructing the interaction between dark energy and dark matter using Gaussian Processes

Tao Yang·Zong-Kuan Guo·Rong-Gen Cai
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Abstract

We present a nonparametric approach to reconstruct the interaction between dark energy and dark matter directly from SNIa Union 2.1 data using Gaussian processes, which is a fully Bayesian approach for smoothing data. In this method, once the equation of state ($w$) of dark energy is specified, the interaction can be reconstructed as a function of redshift. For the decaying vacuum energy case with $w=-1$, the reconstructed interaction is consistent with the standard $\Lambda$CDM model, namely, there is no evidence for the interaction. This also holds for the constant $w$ cases from $-0.9$ to $-1.1$ and for the Chevallier-Polarski-Linder (CPL) parametrization case. If the equation of state deviates obviously from $-1$, the reconstructed interaction exists at $95\%$ confidence level. This shows the degeneracy between the interaction and the equation of state of dark energy when they get constraints from the observational data.

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Tao Yang, Zong-Kuan Guo, Rong-Gen Cai. 2015-05-17. Reconstructing the interaction between dark energy and dark matter using Gaussian Processes. https://doi.org/10.1103/physrevd.91.123533

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