Non-minimal Kinetic coupling to gravity and accelerated expansion

TL;DR

This paper investigates a scalar field with non-minimal kinetic coupling to gravity as a dark energy candidate, analyzing its role in driving accelerated cosmic expansion and finding solutions that resemble a cosmological constant.

Contribution

It introduces a novel kinetic coupling model and derives solutions showing accelerated expansion, including near cosmological constant behavior.

Findings

Scalar field with kinetic coupling can produce power-law accelerated expansion.

The model yields a dynamical equation of state close to a cosmological constant.

Explicit solutions demonstrate the potential of the coupling to explain dark energy.

Abstract

We study a scalar field with kinetic term coupled to itself and to the curvature, as a source of dark energy, and analyze the role of this new coupling in the accelerated expansion at large times. In the case of scalar field dominance, the scalar field and potential giving rise to power-law expansion are found in some cases, and a dynamical equation of state is calculated for a given solution of the field equations. A behavior very close to that of the cosmological constant was found.