Interacting Dark Energy: New parametrization and observational constraints

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 H0 = 69.023 ± 0.722, M = -19.385 ± 0.019, I = 2.901 ± 0.092 and Ω dm0 (1− 3 I ) 1 κ = 0.254 ± 0.023 where H0, M , Ω dm0 and κ 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.

Fab-Four Cosmography to Tackle the Hubble Tension

“…On one hand, changing the equation-of-state of dark energy by making it time-dependent, has also been proposed as a possible explanation [11]. Other theories include adding new interactions, such as interacting dark energy [12,13], interacting dark matter [14] and interacting holographic dark energy [15]; including sterile neutrinos [16], axions [17], or other theorized particles to increase the relativistic degrees of freedom; unifying dark energy and dark matter as a single fluid [18]; introducing cosmological piecewise functions [19]; using a statistical lookback time approach [20], considering the black hole shadows as standard rulers calibrators [21], among many others [22][23][24]. See, for example, [25], for a summary and comparison of several proposals that involve interesting solutions to the H 0 tension.…”