Constraints on the reheating phase after Higgs inflation in the hybrid metric-Palatini approach

TL;DR

This paper investigates the reheating phase after Higgs inflation within a hybrid metric-Palatini framework, deriving constraints on reheating duration and temperature consistent with observational data and baryogenesis requirements.

Contribution

It introduces a novel analysis of reheating constraints in a non-minimally coupled Higgs inflation model using the hybrid metric-Palatini approach, relating reheating parameters to inflationary observables.

Findings

Reheating temperature and e-folds are computed as functions of the spectral index.

Results align with Planck data for specific coupling constants.

Reheating conditions are compatible with baryogenesis temperature requirements.

Abstract

In this paper, we study the post-inflationary era called reheating stage. For this purpose, we consider a model in which the inflaton is non-minimally coupled to the curvature within the hybrid metric-Palatini approach. Furthermore, to investigate the consistency of our results with the observational data, we relate reheating parameters to those of inflation model. By taking into consideration the Higgs potential $V(\phi)=\lambda/4 \phi^4$; we derive the necessary quantities needed to obtain the reheating duration and the reheating temperature. Moreover, we plot reheating e-folds and temperature as a function of the spectral index, respectively. We consider three cases depending on the coupling constant $\xi$. In addition, we use some specific values of the effective equation of state $\omega$, which is presumed to remain relatively constant within the range of $-\frac{1}{3} \leq \omega < \frac{1}{3}$. We find that for $\xi=10^{-4.1}$ our results are in agreement with the recent Planck data as the reheating instant is corresponding to the central value of the spectral index and to a maximum temperature required by the scale of baryogenesis models.