Dark Energy from the Fifth Dimension

TL;DR

This paper explores a five-dimensional embedding approach to gravity, revealing that a Robertson-Walker universe embedded in de Sitter space naturally transitions from deceleration to acceleration, potentially explaining dark energy without additional matter components.

Contribution

It extends the Regge-Teitelboim gravity formulation to non-flat backgrounds and demonstrates a geometric origin of cosmic acceleration in a five-dimensional setting.

Findings

Universe transitions from deceleration to acceleration in this model.

Model fits Hubble data with two parameters.

Acceleration occurs without matter, radiation, or cosmological constant.

Abstract

After extending the Regge-Teitelboim formulation of gravity to include the case where the background embedding space is not flat, we examine the dynamics of the four-dimensional $k=0$ Robertson-Walker (RW) manifold embedded in various five-dimensional backgrounds. We find that when the background is five-dimensional de Sitter space, the RW manifold undergoes a transition from a de-accelerating phase to an accelerating phase. This occurs before the inclusion of matter, radiation or cosmological constant sources, and thus does not require a balance of different components. We obtain a reasonable two-parameter fit of this model to the Hubble parameter data.