Dynamical Compactification, Standard Cosmology and the Accelerating Universe

TL;DR

This paper explores a Kaluza-Klein cosmological model where the evolution of extra dimensions influences the observable universe, potentially explaining cosmic acceleration through effective negative pressure derived from higher-dimensional energy-momentum components.

Contribution

It presents a novel cosmological model linking extra-dimensional dynamics with standard cosmology and cosmic acceleration, including the possibility of negative higher-dimensional gravitational coupling.

Findings

The model reproduces standard Friedmann-Robertson-Walker equations.

Effective pressure can be negative, explaining acceleration.

Higher-dimensional gravitational coupling may be negative.

Abstract

A cosmological model based on Kaluza-Klein theory is studied. A metric, in which the scale factor of the compact space evolves as an inverse power of the radius of the observable universe, is constructed. The Freedmann-Robertson-Walker equations of standard four-dimensional cosmology are obtained precisely. The pressure in our universe is an effective pressure expressed in terms of the components of the higher dimensional energy-momentum tensor. In particular, this effective pressure could be negative and might therefore explain the acceleration of our present universe. A special feature of this model is that, for a suitable choice of the parameters of the metric, the higher dimensional gravitational coupling constant could be negative.