Interacting Dark Energy: New parametrization and observational constraints

TL;DR

This paper introduces a new parametrization for interacting dark energy models, constrains it with observational data, and explores its implications for cosmic evolution and particle physics.

Contribution

It proposes a novel dilution parameter in dark matter-dark energy interaction models and derives observational constraints using supernova and Hubble data.

Findings

New dilution parameter I introduced and constrained.

Cosmological parameters consistent with observations.

Implications for Universe's evolution and particle physics discussed.

Abstract

We have re-investigated Cosmology involving interaction between Dark matter and Dark Energy in the light of a new parametrization. The new parametrization is based on the hypothesis that when Dark matter and Dark Energy will interact, Dark matter will dilute in a different manner than standard non-interacting scenario. We re-built the Cosmological equations with this new parametrization. Observational constraints on the traditional Cosmological parameters and new parameters has also been obtained by using supernova data from Pantheon and Hubble data. The parameter values obtained are $H_0$ = 69.023 $\pm$ 0.722, $M$ = -19.385 $\pm$ 0.019, $I$ = 2.901 $\pm$ 0.092 and $\Omega_{dm0}(1 - \frac{3}{I})\frac{1}{\kappa}$ = 0.254 $\pm$ 0.023 where $H_0$, $M$, $\Omega_{dm0}$ and $\kappa$ are Hubble constant, absolute magnitude of type 1a supernova, present day dark matter density and coupling parameter between dark matter and dark energy respectively while $I$ is a new parameter, dubbed dilution parameter which we introduced in the model representing the modified dilution of dark matter in the interacting scenario. The physical features of the model in regard to evolution of the Universe, deceleration parameter, age of Universe, particle physics implications of interacting scenario has also been explored in depth and conclusions has been drawn.