Revealing the non-adiabatic nature of dark energy perturbations from galaxy clustering data [CEA]

http://arxiv.org/abs/1707.03224


We study structure formation using relativistic cosmological linear perturbation theory in the presence of intrinsic and relative (with respect to matter) non-adiabatic dark energy perturbations. For different dark energy models we assess the impact of non-adiabaticity on the matter growth promoting a comparison with growth rate data. The dark energy models studied lead to peculiar signatures of the (non)adiabatic nature of dark energy perturbations in the evolution of the $f \sigma_{8}(z)$ observable. We show that non-adiabatic DE models become close to be degenerated with respect to the $\Lambda$CDM model at first order in linear perturbations. This would avoid the identification of the non-adiabatic nature of dark energy using current available data. Therefore, such evidence indicates that new probes are necessary to reveal the non-adiabatic features in the dark energy sector.

Read this paper on arXiv…

H. Velten and R. Fazolo
Wed, 12 Jul 17
4/51

Comments: 8 pages, 10 figures