Current Signs of Dynamical Dark Energy. (arXiv:1811.03505v1 [astro-ph.CO])

Current Signs of Dynamical Dark Energy. (arXiv:1811.03505v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Sola_J/0/1/0/all/0/1">Joan Sola</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gomez_Valent_A/0/1/0/all/0/1">Adria Gomez-Valent</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_J/0/1/0/all/0/1">Javier de Cruz Perez</a>

Investigations on dark energy (DE) are currently inconclusive about its time
evolution. Hints of this possibility do glow now and then in the horizon.
Depending on the data sets used and the methodology employed one may reach
different levels of evidence or no evidence at all. Herein we assess the
current status of dynamical dark energy (DDE) in the light of a large body of
updated $SNIa+H(z)+BAO+LSS+CMB$ observations, using the full CMB likelihood.
The performance of the $Lambda$CDM model (with equation of state $w=-1$ for
$Lambda$) is confronted with that of the general XCDM and CPL
parametrizations, as well as with the traditional $Phi$CDM model based on the
scalar field potential $Vsim Phi^{-alpha}$. In particular, we gauge the
impact of the bispectrum in the LSS and BAO parts, and show that the subset of
$CMB+BAO+LSS$ observations may contain the bulk of the DDE signal. The
departure from $w=-1$ is significant: roughly $2.6sigma$ for XCDM and
$2.9sigma$ for $Phi$CDM. In both cases the full Bayesian evidence for DDE is
found to be positive even for a prior range extending over several standard
deviations from the mean when the bispectrum is taken into account. We report
also on positive signs from the preliminary results of Planck 2018 data using
the compressed CMB likelihood.

Investigations on dark energy (DE) are currently inconclusive about its time
evolution. Hints of this possibility do glow now and then in the horizon.
Depending on the data sets used and the methodology employed one may reach
different levels of evidence or no evidence at all. Herein we assess the
current status of dynamical dark energy (DDE) in the light of a large body of
updated $SNIa+H(z)+BAO+LSS+CMB$ observations, using the full CMB likelihood.
The performance of the $Lambda$CDM model (with equation of state $w=-1$ for
$Lambda$) is confronted with that of the general XCDM and CPL
parametrizations, as well as with the traditional $Phi$CDM model based on the
scalar field potential $Vsim Phi^{-alpha}$. In particular, we gauge the
impact of the bispectrum in the LSS and BAO parts, and show that the subset of
$CMB+BAO+LSS$ observations may contain the bulk of the DDE signal. The
departure from $w=-1$ is significant: roughly $2.6sigma$ for XCDM and
$2.9sigma$ for $Phi$CDM. In both cases the full Bayesian evidence for DDE is
found to be positive even for a prior range extending over several standard
deviations from the mean when the bispectrum is taken into account. We report
also on positive signs from the preliminary results of Planck 2018 data using
the compressed CMB likelihood.

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