New coupled quintessence cosmology

TL;DR

This paper introduces a new coupled quintessence cosmological model where dark energy decays into cold dark matter, and tests its viability using recent observational data from supernovae, BAO, and CMB.

Contribution

It proposes a novel scenario with dark energy decaying into dark matter, extending previous coupled quintessence models and analyzing its observational consistency.

Findings

Model fits well with current observational data.

Dark energy decay parameter $psilon$ constrained by observations.

Supports viability of dark energy decay into dark matter.

Abstract

A component of dark energy has been recently proposed to explain the current acceleration of the Universe. Unless some unknown symmetry in Nature prevents or suppresses it, such a field may interact with the pressureless component of dark matter, giving rise to the so-called models of coupled quintessence. In this paper we propose a new cosmological scenario where radiation and baryons are conserved, while the dark energy component is decaying into cold dark matter (CDM). The dilution of CDM particles, attenuated with respect to the usual $a^{-3}$ scaling due to the interacting process, is characterized by a positive parameter $\epsilon$, whereas the dark energy satisfies the equation of state $p_x=\omega \rho_x$ ($\omega < 0$). We carry out a joint statistical analysis involving recent observations from type Ia supernovae, baryon acoustic oscillation peak, and Cosmic Microwave Background shift parameter to check the observational viability of the coupled quintessence scenario here proposed.