Different Prospects of the Universe Depending on Dark Energy and/or a New Kind of Extra Dimension

TL;DR

This paper proposes a novel cosmic acceleration mechanism based on extra dimensions, suggesting that dark energy may not be necessary for universe acceleration, and explores different universe scenarios with constraints on extra dimensions.

Contribution

It introduces a new acceleration mechanism depending on extra dimensions and provides constraints under various universe prospects, challenging the necessity of dark energy.

Findings

Accelerating expansion can occur without dark energy.

Extra dimensions can influence cosmic acceleration.

Multiple universe scenarios with different extra dimension constraints.

Abstract

Generally making the cosmological scale factor $R$ be a function of the coordinate of the extra dimension $\sigma $ that is also a function of time $t$, we achieve a new kind of cosmic acceleration mechanism depending on extra dimension. We give the constraints on $\sigma $ under four different prospects of the universe, and indicate that dark energy is not required for both the small extra dimension and the accelerating expansion of our universe. This results in this paper show that the accelerating expansion of our universe may come from both dark energy and the achieved new mechanism here, or the latter alone.