NO Curvatons or Hybrid Quintessential Inflation

TL;DR

This paper proposes a novel curvaton scenario utilizing a non-oscillatory potential and inhomogeneous preheating, where the preheat field plays a key role in generating curvature perturbations, offering a hybrid approach to quintessential inflation.

Contribution

It introduces a non-oscillatory curvaton model combined with inhomogeneous preheating, sharing the curvaton task with the preheat field, and presents a hybrid quintessential inflation framework.

Findings

Preheat field density decreases slower than matter, allowing growth over time.

Curvature perturbation is generated through inhomogeneous preheating and preheat field decay.

The model provides an alternative to standard curvaton scenarios with hybrid inflation features.

Abstract

We consider a curvaton scenario in which the late-time domination and the generation of the curvature perturbation is achieved by a non-oscillatory (NO) curvaton potential. Instead of considering the conventional curvaton oscillation, we consider ``weak trapping'' after preheating, which modifies the evolution of the curvaton density after preheating. The primordial isocurvature perturbation related to the curvaton is once converted into the fluctuation of the number density of the preheat field through inhomogeneous preheating. Then the evolution of the curvatons and the preheat field is controlled by the preheat-field number density. The density of these fields decreases slightly slower than the standard matter density which suggests that these fields will grow with time. Finally, the preheat field decays to reheat the Universe leaving behind the curvature perturbation. In our scenario the task of the standard curvaton is not executed solely by the curvaton itself but is partially shared with the preheat field. NO curvatons can be considered as the hybrid version of the quintessential inflationary model.