Cosmological dynamics of scalar fields with kinetic corrections: Beyond the exponential potential

TL;DR

This paper extends the analysis of scalar field cosmologies with kinetic corrections to arbitrary potentials, demonstrating their ability to model dark energy and crossing the phantom barrier, with stability considerations.

Contribution

It generalizes previous work by considering arbitrary potentials and explores their cosmological dynamics, including late-time acceleration and phantom crossing.

Findings

Models can describe dark energy phenomena.

Scalar fields can dynamically cross the phantom barrier.

Classical stability and viability are discussed.

Abstract

We expand the dynamical systems investigation of cosmological scalar fields characterised by kinetic corrections presented in [N. Tamanini, Phys. Rev. D 89 (2014) 083521]. In particular we do not restrict the analysis to exponential potentials only, but we consider arbitrary scalar field potentials and derive general results regarding the corresponding cosmological dynamics. Two specific potentials are then used as examples to show how these models can be employed not only to describe dark energy, but also to achieve dynamical crossing of the phantom barrier at late times. Stability and viability issues at the classical level are also discussed.