Remya Nair, Sanjay Jhingan
We look for evidence for the evolution in dark energy density by employing Principle Component Analysis (PCA). Distance redshift data from supernovae and baryon acoustic oscillations (BAO) and Observational Hubble data alongwith WMAP7 distance priors are used to put constraints on curvature parameter and dark energy parameters. The data sets are consistent with a flat Universe. The constraints on the dark energy evolution parameters obtained from supernovae and Hubble data (including CMB distance priors) are consistent with a flat Lambda-CDM Universe. On the other hand, the parameter estimates obtained from the addition of BAO data indicate a possible evolution in dark energy density. In this case the first two principle components, which characterize a non-constant contribution from dark energy, are non-zero at 1-sigma. This could be a systematic effect and future BAO data holds key to making more robust claims.
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http://arxiv.org/abs/1212.6644
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