1112.6025 (Houri Ziaeepour)

Discrimination between Lambda-CDM, quintessence, and modified gravity
models using wide area surveys    [PDF]

Houri Ziaeepour

In the past decade or so observations of supernovae, Large Scale Structures (LSS), and Cosmic Microwave Background (CMB) have confirmed the presence of what is called dark energy, and have measured its density as well as the value of other cosmological parameters according to concordance - $\Lambda$CDM model with few percent uncertainties. Next generation of surveys should allow to constrain this model with better precisions or distinguish between a $\Lambda$CDM and alternative models such as modified gravity and (interacting)-quintessence models. In this work we parametrize both homogeneous and anisotropic components of matter density in the context of interacting dark energy models with the goal of discriminating between $f(R)$ modified gravity and its generalizations, and interacting dark energy models, for which we also propose a phenomenological description of energy-momentum conservation equations inspired by particle physics. It is based on the fact that the simplest interactions between particles/fields are elastic scattering and decay. The parametrization of growth rate proposed here is nonetheless general and can be used to constrain other interactions. As an example of applications, we present a crude estimation of the accuracy of the measurement of these parameters using Euclid and Planck surveys data.

View original: http://arxiv.org/abs/1112.6025