Abstract Details

Name: JOSEPH P J
Affiliation: IIT Bombay
Conference ID: ASI2021_268
Title : Cosmological perturbations in the interacting dark sector: Mapping fields and fluids
Authors and Co-Authors : Joseph P Johnson (IIT Bombay), S. Shankaranarayanan (IIT Bombay)
Abstract Type : Poster
Abstract Category : General Relativity and Cosmology
Abstract : I will discuss the dark energy - dark matter interaction in the late universe. Demanding that the interaction strength in the dark sector must have a field theory description, we obtain a unique form of interaction strength. I will show the equivalence between the fields and fluids for the f (R, χ) model where f is an arbitrary, smooth function of R and the scalar field χ, which represents dark matter. Up to first order in perturbations, we show that the one-to-one mapping between the field theory description and the phenomenological fluid description of interacting dark energy and dark matter exists only for this unique form of interaction. Then I will discuss the background evolution of the universe with interacting dark sector including the stability analysis of the background solutions. (arXiv:2006.04618, submitted to Phys. Rev. D.)