A Dynamical Approach to the Cosmological Constant

TL;DR

This paper proposes a novel dynamical scalar field model with a singular kinetic term that naturally stalls the cosmological constant near zero, offering a stable, radiatively robust approach to addressing the cosmological constant problem.

Contribution

It introduces a new scalar field model with a divergent kinetic coefficient that stabilizes the cosmological constant without fine-tuning, improving upon previous approaches.

Findings

Model stabilizes the cosmological constant near zero.

Stable under radiative corrections despite singular kinetic term.

Reduces fine-tuning by 60 orders of magnitude.

Abstract

We consider a dynamical approach to the cosmological constant. There is a scalar field with a potential whose minimum occurs at a generic, but negative, value for the vacuum energy, and it has a non-standard kinetic term whose coefficient diverges at zero curvature as well as the standard kinetic term. Because of the divergent coefficient of the kinetic term, the lowest energy state is never achieved. Instead, the cosmological constant automatically stalls at or near zero. The merit of this model is that it is stable under radiative corrections and leads to stable dynamics, despite the singular kinetic term. The model is not complete, however, in that some reheating is required. Nonetheless, our approach can at the very least reduce fine-tuning by 60 orders of magnitude or provide a new mechanism for sampling possible cosmological constants and implementing the anthropic principle.