A five dimensional model with a fifth dimension as fundamental as time in terms of a cosmological approach

TL;DR

This paper proposes a five-dimensional cosmological model where the fifth dimension is as fundamental as time, enabling accelerated expansion without dark energy and embedding all relevant 4D cosmologies.

Contribution

It introduces a novel way to incorporate the fifth dimension as a time-like component, providing a new framework for cosmological models without dark energy.

Findings

Achieves accelerated expansion without dark energy.

Embeds all relevant 4D cosmologies in a 5D flat spacetime.

Suggests a linearly expanding universe as the simplest frame.

Abstract

In five dimensional cosmological models, the convention is to include the fifth dimension in a way similar to the other space dimensions. In this work we attempt to introduce the fifth dimension in a way that a time dimension would be introduced. With such an internal space, we are able to obtain accelerated expansion without introducing dark energy. We obtain a five dimensional flat, meaning both Ricci flat and conformally flat, spacetime into which all relevant four dimensional cosmologies can be locally embedded. We also argue on the choice of the cosmological frame. The choice that is simplest and most convenient in terms of dimensional analysis, amounts to a linearly expanding universe.