New tracker models of dark energy

TL;DR

This paper introduces a new class of dark energy models based on $ ext{alpha}$-attractor potentials, which naturally lead to the current accelerated expansion of the universe from diverse initial conditions, avoiding fine-tuning issues.

Contribution

It proposes a novel dark energy model class using $ ext{alpha}$-attractor potentials, capable of explaining cosmic acceleration without fine-tuning.

Findings

Models exhibit early-time tracker behavior.

Current acceleration achieved from broad initial conditions.

Consistent with observational data on accelerated expansion.

Abstract

We describe a new class of dark energy (DE) models which behave like cosmological trackers at early times. These models are based on the $\alpha$-attractor set of potentials, originally discussed in the context of inflation. The new models allow the current acceleration of the universe to be reached from a wide class of initial conditions. Prominent examples of this class of models are the potentials $\coth\varphi$ and $\cosh\varphi$. A remarkable feature of this new class of models is that they lead to large enough negative values of the equation of state at the present epoch, consistent with the observations of accelerated expansion of the universe, from a very large initial basin of attraction. They therefore avoid the fine tuning problem which afflicts many models of DE.