Gravitational Waves from Preheating in Gauss-Bonnet Inflation

TL;DR

This paper investigates how the Gauss-Bonnet term influences gravitational wave production during preheating after inflation, linking theoretical models with observational constraints from cosmic microwave background data.

Contribution

It introduces a novel analysis of Gauss-Bonnet inflation's impact on gravitational wave spectra and preheating parameters, connecting theoretical predictions with observational data.

Findings

Gravitational wave energy density spectrum aligns with observations for specific parameters.

Preheating parameters are sensitive to the Gauss-Bonnet coupling and model parameters.

The model can satisfy Planck constraints on gravitational waves.

Abstract

We study gravitational wave production in an expanding Universe during the first stages following inflation, and investigate the consequences of the Gauss-Bonnet term on the inflationary parameters for a power-law inflation model with a GB coupling term. Moreover, we perform the analyses on the preheating parameters involving the number of e-folds $N_{pre}$, and the temperature of thermalization $T_{th},$ and show that it's sensitive to the parameters $n$, and $\gamma$, the parameter $\gamma$ is proposed to connect the density energy at the end of inflation to the preheating energy density. We set a correlation of gravitational wave energy density spectrum with the spectral index $n_{s}$ detected by the cosmic microwave background experiments$.$ The density spectrum $\Omega_{gw}$ shows good consistency with observation for $\gamma = 10^{3}$ and $10^{6}$. Our findings suggest that the generation of gravitational waves (GWs) during preheating can satisfy the constraints from Planck's data.