GW170817 Viable Einstein-Gauss-Bonnet Inflation Compatible with the Atacama Cosmology Telescope Data

TL;DR

This paper explores Einstein-Gauss-Bonnet inflation models compatible with GW170817, Atacama Cosmology Telescope, and Planck data, demonstrating their viability and providing specific model examples within two theoretical classes.

Contribution

It introduces two classes of Einstein-Gauss-Bonnet inflation models compatible with observational constraints and analyzes their viability against recent cosmological data.

Findings

Both classes satisfy GW170817 constraints.

Models can fit Atacama and Planck data.

Einstein-Gauss-Bonnet theories are promising for inflation.

Abstract

In this work we investigate several Einstein-Gauss-Bonnet models that are compatible with the GW170817 event, the Atacama Cosmology Telescope data and the BICEP/Keck updated Planck constraints on the tensor-to-scalar ratio. We consider two distinct classes of Einstein-Gauss-Bonnet theories, which are equally successful for GW170817-compatible model building and we examine their viability against the Atacama Cosmology Telescope data and the updated Planck constraints on the tensor-to-scalar ratio. The two models are distinct since the first class relates directly the non-minimal Gauss-Bonnet scalar coupling function with the scalar potential and yields $c_T^2=1$ while in the second class, the non-minimal Gauss-Bonnet scalar coupling function and the scalar potential are freely but conveniently chosen and the class of models respects the constraint $\left| c_T^2 - 1 \right| < 6 \times 10^{-15}$. We provide several examples of models belonging to both the two classes of GW170817-compatible Einstein-Gauss-Bonnet theories and we demonstrate that Einstein-Gauss-Bonnet theories provide a promising theoretical framework for inflationary dynamics.