Preheating after technicolor inflation

Abstract

We investigate the particle production due to parametric resonances in model of inflation where the lightest composite state stemming from the minimal walking technicolor theory plays the role of the inflaton. For model of inflation, the effective theory couples non-minimally to gravity. Regarding the preheating, we study in details a model of a composite inflaton field $\phi$ coupled to another scalar field $\chi$ with the interaction term $g^{2}\phi^{2}\chi^{2}$. Particularly, in the Minkowski space, the stage of parametric resonances can be described by the Mathieu equation. Interestingly, we discover that broad resonances can be typically achieved and potentially efficient in our model causing the number of particle density in this process exponentially increases.