Consistency of warm k-inflation

TL;DR

This paper extends k-inflation to warm inflation scenarios, analyzing stability and slow-roll conditions for different kinetic functions and dissipation coefficients, identifying viable models with field-dependent dissipation.

Contribution

It introduces a warm k-inflation framework, derives new slow-roll parameters, and analyzes stability for power-law and exponential kinetic functions with different dissipation coefficients.

Findings

Constant dissipation coefficient is not viable for warm k-inflation.

Field-dependent dissipation coefficients yield self-consistent warm inflation models.

Proper e-folds are achieved in the studied cases.

Abstract

We extend the k-inflation which is a type of kinetically driven inflationary model under the standard inflationary scenario to a possible warm inflationary scenario. The dynamical equations of this warm k-inflation model are obtained. We rewrite the slow-roll parameters which are different from the usual potential driven inflationary models and perform a linear stability analysis to give the proper slow-roll conditions in the warm k-inflation. Two cases, a power-law kinetic function and an exponential kinetic function, are studied, when the dissipative coefficient $\Gamma=\Gamma_0$ and $\Gamma=\Gamma(\phi)$, respectively. A proper number of e-folds is obtained in both concrete cases of warm k-inflation. We find a constant dissipative coefficient ($\Gamma=\Gamma_0$) is not a workable choice for these two cases while the two cases with $\Gamma=\Gamma(\phi)$ are self-consistent warm inflationary models.