Khalil El Bourakadi | Searcharxiv

arXiv2022

Hubble tension and Reheating: Hybrid Inflation Implications

We investigate a new possible solution to the Hubble constant tension. we propose a simple resolution to the problem assuming that a first-order phase transition related to H0 transition occurred in the early Universe. The early evolution of the Universe is a result of hybrid inflation that has lasted for a specific period until symmetry breaking takes place. Fitting our model to measurements from Planck and SH0ES data provides a key explanation of discrepancies of H0 measurements. The quantum fluctuations calculated in this model have significant results on the reheating parameters Nre and Tre. Therefore, new constraints must be taken into consideration to fit these parameters to recent results.

gr-qc↗

arXiv2021

Preheating and Reheating after Standard Inflation

We study the two-phase scenario following inflation, where the initial step is preheating, accompanied by a step of perturbative reheating at which inflaton field decays transferring all of its energy to create relativistic particles, the interaction of these particles will evolve towards a state of thermal equilibrium with a temperature Tre called the reheating temperature. It is observed that the scenario of reheating normally predicts the maximum reheating temperature that corresponds to an almost instantaneous transition from inflation to the radiation domination era. This will naturally lead to a nonperturbative preheating. In this framework, we propose constraints on the reheating duration parameters expressed in terms of the cosmic microwave background (CMB) inflationary scalar spectral index. In this work, we study the compatibility of polynomial and Higgs models of inflation with the observational data obtained from Planck 2018.

gr-qc↗