Cosmological viability of a double field unified model from warm inflation

TL;DR

This study explores a double scalar field model inspired by warm inflation, assessing its ability to unify dark energy, dark matter, and inflation, and tests its compatibility with current cosmological data.

Contribution

It introduces a triple unification scheme for dark energy, dark matter, and inflation within a double scalar field model and evaluates its observational viability.

Findings

Model parameters fit within theoretical ranges.

Scalar field evolution resembles dark sector features.

Statistical evidence comparable to ΛCDM.

Abstract

In this paper, we investigate the cosmological viability of a double scalar field model motivated by warm inflation. To this end, we first set up the theoretical framework in which dark energy, dark matter and inflation are accounted for in a triple unification scheme. We then compute the overall dynamics of the model, analyzing the physical role of coupling parameters. Focussing on the late-time evolution, we test the model against current data. Specifically, using the low-redshift Pantheon Supernovae Ia and Hubble cosmic chronometers measurements, we perform a Bayesian analysis through the Monte Carlo Markov Chains method of integration on the free parameters of the model. We find that the mean values of the free parameters constrained by observations lie within suitable theoretical ranges, and the evolution of the scalar fields provides a good resemblance to the features of the dark sector of the universe. Such behaviour is confirmed by the outcomes of widely adopted selection criteria, suggesting a statistical evidence comparable to that of the standard $\Lambda$CDM cosmology. We finally discuss the presence of large uncertainties over the free parameters of the model and we debate about fine-tuning issues related to the coupling constants.