arXiv subjects

Apirak Payaka

Publications and source records attributed to Apirak Payaka.

2 recordsLinked to original sources

arXiv2022

Warm deformed $R^{2}$ inflation

In this work, we study warm inflationary scenario based on a deformation of $R^{2}$ gravity. We start considering $R^{p}$ and assume $p=2(1+δ)$ with $δ\ll 1$ so that we simply obtain warm $R^{2}$ inflation when setting $δ=0$. We then derive the potential in the Einstein frame and consider a dissipation parameter of the form $Γ= C_{1}T$ with $C_1$ being a coupling parameter. We focus only on the strong regime of which the interaction between inflaton and radiation fluid has been taken into account. We compute inflationary observables and constrain the parameters of our model using latest observational data reported by Planck. From our analysis, we discover that with proper choices of parameters the derived $n_s$ and $r$ are in good agreement with the Planck 2018 observational constraints. Particularly, we constrain the potential scale $U_{0}$ of the models.

gr-qc↗

arXiv2022

Warm inflation in general scalar-tensor theory of gravity

In this work, we investigate warm inflationary models in the context of a general scalar-tensor theory of gravity which is coupled to radiation through a dissipation term. We first derive the potential of exponential and hyperbolic tangent forms. We consider a dissipation parameter of the form $Γ= C_{1}T$ with $C_1$ being a coupling parameter and focus only on the strong regime of which the interaction between inflaton and radiation fluid has been taken into account. We compute inflationary observables and constrain the parameters of our model using current Planck 2018 data. From our analysis, we discover that the weak coupling limit $ξ\ll 1$ is needed in order to have the derived $n_s$ and $r$ consistent with the Planck 2018 observational constraints. Particularly, we constrain the potential scale $V_{0}$ of the models.

gr-qc↗