Abstract Details

Name: JOSEPH P J
Affiliation: IIT Bombay
Conference ID: ASI2020_361
Title : Low-energy modified gravity signatures on the large-scale structures
Authors and Co-Authors : Joseph P Johnson, S. Shankaranarayanan
Abstract Type : Oral
Abstract Category : General Relativity and Cosmology
Abstract : A large number of dark energy and modified gravity models lead to the same expansion history of the Universe, hence making it difficult to distinguish them from observations. In this talk, I will look at $f(R)$ gravity with a pressureless matter without making any assumption about the form of $f(R)$ . Using the late-time expansion history realizations constructed by Shafieloo et al. 2018, I will explicitly show that for any $f(R)$ model that leads to late-time accelerated expansion, the Bardeen potentials $\Psi$ and $\Phi$ evolve differently. I will also show that that $|\Psi + \Phi|$ and its time derivative evolves differently than the $\Lambda$CDM model at lower redshifts, and $\Psi / \Phi$ shows significant deviation from unity for larger wavenumbers. Then I will discuss the implications of the results for the cosmological observations. This talk will be based on the following Published paper. "Low-energy modified gravity signatures on the large-scale structures" Authors: Joseph P. Johnson and S. Shankaranarayanan Phys. Rev. D 100, 083526 – Published 15 October 2019