Warm $\frac{\lambda}{4}\phi^{4}$ inflationary universe model in light of Planck 2015 results

TL;DR

This paper demonstrates that a warm inflation model with a quartic potential aligns with Planck 2015 data, predicting negligible tensor-to-scalar ratios in strong dissipation and observable ratios in weak dissipation regimes.

Contribution

It shows that warm $rac{ ext{lambda}}{4} ext{phi}^4$ inflation, previously excluded, fits current data when considering temperature-dependent decay rates.

Findings

Model fits Planck data constraints

Predicts negligible tensor-to-scalar ratio in strong dissipation

Allows observable tensor-to-scalar ratio in weak dissipation

Abstract

In the present work we show that warm chaotic inflation characterized by a simple $\frac{\lambda}{4}\phi^{4}$ self-interaction potential for the inflaton, excluded by current data in standard cold inflation, and by an inflaton decay rate proportional to the temperature, is in agreement with the latest Planck data. The parameters of the model are constrained, and our results show that the model predicts a negligible tensor-to-scalar ratio in the strong dissipative regime, while in the weak dissipative regime the tensor-to-scalar ratio can be large enough to be observed.