Reheating constraints in modified natural inflation with the decaying inflaton

This research investigates the reheating constraints in two modified natural inflation models. The models are Special Generalized Natural Inflation (SNI) model and the Natural Inflation Inspired (NII) model. In this paper, we consider the decaying inflaton into radiation, which leads to an time-dependent effective Equation-of-State (EoS) parameter. We assume that the decay rate of inflaton takes the form of a linear function of the Hubble rate F = 3δH. We derive analytic solutions to the conservation equations to obtain the allowed range values of parameter δ. Reheating constraints and their prediction for inflationary models have been investigated. We also plot the results in the case of the constant EoS parameter for comparison. We find that the time-dependent EoS parameter gives the models more precise constraints. We can conclude that it has a significant effect on reheating constraints