We study the predictions for structure formation in an induced gravity dark energy model with a quartic potential. By developing a dedicated Einstein-Boltzmann code, we study self-consistently the dynamics of homogeneous cosmology and of linear perturbations without using any parametrization. By evolving linear perturbations with initial conditions in the radiation era, we accurately recover the quasi-static analytic approximation in the matter dominated era. We use PLANCK 2013 data and a compilation of baryonic acoustic oscillation (BAO) data to constrain the coupling γ to the Ricci curvature and the other cosmological parameters. By connecting the gravitational constant in the Einstein equation to the one measured in a Cavendish-like experiment, we find γ < 0.0012 at 95% CL with PLANCK 2013 and BAO data. This is the tightest cosmological constraint on γ and on the corresponding derived post-Newtonian parameters. Because of a degeneracy between γ and the Hubble constant H0, we show how larger values for γ are allowed, but not preferred at a significant statistical level, when local measurements of H0 are combined in the analysis with PLANCK 2013 data.
Umilta C., Ballardini M., Finelli F., Paoletti D. (2015). CMB and BAO constraints for an induced gravity dark energy model with a quartic potential. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 2015(8), 017-017 [10.1088/1475-7516/2015/08/017].
CMB and BAO constraints for an induced gravity dark energy model with a quartic potential
Ballardini M.;
2015
Abstract
We study the predictions for structure formation in an induced gravity dark energy model with a quartic potential. By developing a dedicated Einstein-Boltzmann code, we study self-consistently the dynamics of homogeneous cosmology and of linear perturbations without using any parametrization. By evolving linear perturbations with initial conditions in the radiation era, we accurately recover the quasi-static analytic approximation in the matter dominated era. We use PLANCK 2013 data and a compilation of baryonic acoustic oscillation (BAO) data to constrain the coupling γ to the Ricci curvature and the other cosmological parameters. By connecting the gravitational constant in the Einstein equation to the one measured in a Cavendish-like experiment, we find γ < 0.0012 at 95% CL with PLANCK 2013 and BAO data. This is the tightest cosmological constraint on γ and on the corresponding derived post-Newtonian parameters. Because of a degeneracy between γ and the Hubble constant H0, we show how larger values for γ are allowed, but not preferred at a significant statistical level, when local measurements of H0 are combined in the analysis with PLANCK 2013 data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.