Constraining non-minimally coupled β-exponential inflation with CMB data

Abstract

The β-exponential inflation is driven by a class of primordial potentials, derived in the framework of braneworld scenarios, that generalizes the well-known power law inflation. In this paper we update previous constraints on the minimal coupled β-exponential model [1] and extend the results also deriving the equations for the non-minimal coupled scenario. The predictions of both models are tested in light of the latest temperature and polarization maps of the Cosmic Microwave Background and clustering data. We also compare the predictions of these models with the standard ΛCDM cosmology using the Deviance Information Criterion (DIC), and find that the observational data show a moderate preference for the non-minimally coupled β-exponential inflationary model.

Warm $$\beta $$-exponential inflation and the swampland conjectures

“…This relation imposes a constraint on both β and λ, where essentially, β must be larger than λ, with β ≥ 1/2. In [45,46], this limit is satisfied in the priors and numerical analysis results. Our analysis will also check if this constraint is still respected when computing the inflationary observables.…”

“…Indeed, when one looks to inflationary parameters n s and r , some extension that allows concordance with data to be restored is usu-ally required. While for instance, a non-minimal coupling of the inflaton with gravity might alleviate much of these issues [46,79], it is interesting (and plausible) to consider a situation where the energy stored in the inflaton is converted to other particles as inflation happens, resulting in a warm inflationary universe that can lead towards a radiationdominated universe afterwards. Another issue related to inflationary models is their agreement with the recently proposed swampland conjectures [47,65], which result from attempts to incorporate models based on field theory into general ones such as string theory.…”

“…In this work, we have considered how the β-exponential inflationary model [44][45][46] behaves when we allow dissipation of the inflaton energy into radiation in the warm inflation picture. In the original model, for N = 50−60, it is not possible to have a low enough r while satisfying the constraints for n s [46].…”

“…In this work, we have considered how the β-exponential inflationary model [44][45][46] behaves when we allow dissipation of the inflaton energy into radiation in the warm inflation picture. In the original model, for N = 50−60, it is not possible to have a low enough r while satisfying the constraints for n s [46]. In contrast, in the warm inflation scenario, we can easily have concordance with data when inflation happens in the weak dissipation regime for a restricted interval of β.…”

“…As shown in [45], such a model can arise from brane dynamics and showed a good agreement with Planck 2015 data. An updated analysis with Planck 2018 and clustering data showed that the model with a non-minimal coupling of the field with gravity seems to be a more viable approach for this class of models [46]. Here we investigate how the predictions of the β-exponential inflationary model change when considering the warm inflation picture, as recent studies have investigated the viability of exponential potentials in this context.…”