IA/U.Lisboa Seminar - Testing dark energy and modified gravity models with EFTCAMB: The Hořava gravity case - 19 abril 2016

Given the wide sample of dark energy and modified gravity models (DE/MG) that address late time accelerated scenario and the high precision data (WMAP, PLANCK, SDSS, EUCLID in the near future), it becomes crucial to test DE/MG theories against data on large scale.

 

 

In the quest of a model independent parametrization for gravity theories, the effective field theory formalism has been applied to the phenomenon of cosmic acceleration.

 

 

It is developed using a perturbative approach in which an extra scalar degree of freedom appears only at the level of perturbations. I will present the implementation of this framework into CAMB/CosmoMC creating, what we dubbed, EFTCAMB/EFTCosmoMC. These patches allow to test gravity theories with the most recent data releases. To illustrate the use of these patches, I will show the results in the case of Horava gravity, which is attracting attention as feasible candidate of quantum gravity.

The theory is constructed such that, time and space are treated differently leading to the violation of the Lorentz invariance. Thus, it is of primary relevance to test Lorentz violation at all scales, in particular I will show that its cosmological implications are quite dramatic and current data already place stringent bounds on the theory parameters.