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DOE OSTI · 1851369

Informational approach to cosmological parameter estimation

Stephens, Michelle·Vannah, Sara·Gleiser, Marcelo
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Abstract

Here, we introduce a new approach for cosmological parameter estimation based on the information-theoretical Jensen-Shannon divergence ($\mathscr{D}$ JS ), calculating it for models in the restricted parameter space {H 0 , w 0 , w a }, where H 0 is the value of the Hubble constant today, and w 0 and w a are dark energy parameters, with the other parameters held fixed at their best-fit values from the Planck 2018 data. As an application, we investigate the H 0 tension between the Planck temperature power spectrum data (TT) and the local astronomical data by comparing the ΛCDM model with the wCDM and the w 0 w a CDM dynamic dark energy models. We find agreement with other works using the standard Bayesian inference for parameter estimation; in addition, we show that while the $\mathscr{D}$ JS is equally minimized for both values of H 0 along the (w 0 , w a ) plane, the lines of degeneracy are different for each value of H 0 . This allows for distinguishing between the two, once the value of either w 0 or w a is known.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS79 ASTRONOMY AND ASTROPHYSICScosmic microwave backgroundcosmological parametersdark energy

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Stephens, Michelle, Vannah, Sara, Gleiser, Marcelo. 2020-12-03. Informational approach to cosmological parameter estimation. https://doi.org/10.1103/physrevd.102.123514

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