Cosmological viability of a double field unified model from warm
  inflation
  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.
