Dark energy from scalar field with Gauss Bonnet and non-minimal kinetic coupling

TL;DR

This paper investigates a scalar field model with non-minimal kinetic and Gauss-Bonnet couplings, revealing diverse cosmological solutions including dark energy-like behavior and phases of acceleration and deceleration.

Contribution

It introduces a new scalar field model with combined non-minimal kinetic and Gauss-Bonnet couplings, analyzing its rich cosmological dynamics and solutions.

Findings

Existence of power-law expansion solutions.

Phenomenologically acceptable dark energy solutions.

Models exhibiting both decelerated and accelerated phases.

Abstract

We study a model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, and additional coupling to the Gauss Bonnet 4-dimensional invariant. The model presents rich cosmological dynamics and some of its solutions are analyzed. A variety of scalar fields and potentials giving rise to power-law expansion have been found. The dynamical equation of state is studied for two cases, with and without free kinetic term . In both cases phenomenologically acceptable solutions have been found. Some solutions describe essentially dark energy behavior, and and some solutions contain the decelerated and accelerated phases.