Dynamical dark energy from Kretschmann scalar at low redshifts

TL;DR

This paper introduces a cosmological model replacing the cosmological constant with the Kretschmann scalar, enabling a dynamical dark energy framework consistent with observational data at low redshifts.

Contribution

It proposes a novel model where the Kretschmann scalar replaces the cosmological constant, fitting observational data and reproducing phenomenological dark energy behaviors.

Findings

Model fits supernovae and cosmic chronometer data well.

Equation-of-state parameter w(z) matches recent observational results.

Indicates a phantom-crossing regime at low redshifts.

Abstract

In this work, we present a cosmological model in which the cosmological constant term is replaced by the Kretschmann scalar at the level of the action. In this way, it becomes possible to implement a model of dynamical dark energy. After constraining the free parameters using observational data from supernovae and cosmic chronometers, we show that the model provides a good fit to the observational data. In particular, we show that, at least at low redshifts, the behavior of the equation-of-state parameter $w(z)$ closely reproduces that obtained in phenomenological models that have been recently studied based on the latest observational data from the DESI collaboration. Likewise, the present model also indicates the occurrence of a phantom-crossing regime.