A Dark Energy Model in Kaluza-Klein Cosmology

TL;DR

This paper explores a dynamic dark energy model within Kaluza-Klein cosmology, examining variable gravitational constant G, universe acceleration, and conditions for age and signature flipping, aligning with observations.

Contribution

It introduces a novel dynamic Lambda model with varying G in Kaluza-Klein cosmology, analyzing its physical features and observational consistency.

Findings

Signature flipping of the deceleration parameter observed.

The model can explain the current age of the universe.

Time variation of G requires a specific Lambda condition.

Abstract

We study a dynamic $\Lambda$ model with varying gravitational constant $G$ under the Kaluza-Klein cosmology. Physical features and the limitations of the present model have been explored and discussed. Solutions are found mostly in accordance with the observed features of the accelerating universe. Interestingly, signature flipping of the deceleration parameter is noticed and the present age of the Universe is also attainable under certain stringent conditions. We find that the time variation of gravitational constant is not permitted without vintage $\Lambda$.