# Aspects of wave turbulence in preheating II: Rebirth of the nonminimal coupled models

## TL;DR

This paper investigates wave turbulence during preheating in a nonminimally coupled inflaton model with a quartic potential, highlighting energy transfer mechanisms and thermalization effects through numerical simulations.

## Contribution

It demonstrates the role of wave turbulence in energy transfer during preheating in nonminimally coupled models, including the impact of backreaction on the universe's dynamics.

## Key findings

- Turbulence influences the power spectra of inflaton fluctuations.
- Energy transfer from inflaton to inhomogeneous modes is characterized.
- Effective equation of state is determined considering backreaction.

## Abstract

We study the nonlinear stage of preheating in a model consisting of a single inflaton field $\phi$ nonminimally coupled to the spacetime curvature and considering a self-coupling quartic potential V ($\phi$) = $\lambda \phi^4/4$. As the first motivation, we mention that this nonminimally coupled model agrees with the observational data. The second and the central issue of the present work is to exhibit aspects of wave turbulence associated with the mechanism of energy transfer from the inflaton field to the inhomogeneous fluctuations towards a state of thermalization. The imprints of the turbulence phase are mainly shown in the power spectra in time and wavenumber of relevant quantities such as the variance and the energy density of the inflaton field. We performed the simulations for several values of the nonminimally coupled models and taking into account the backreaction of the inflaton fluctuations in the dynamics of the Universe, and that allowed to determine the effective equation of state.