Cosmological constant and late transient acceleration of the universe in the Horava-Witten Heterotic M-Theory on S^{1}/Z_{2}

TL;DR

This paper explores how the Horava-Witten heterotic M-Theory with orbifold branes can explain the current small cosmological constant and predicts a future decelerating universe, addressing issues of a de Sitter universe.

Contribution

It demonstrates a mechanism within M-Theory that naturally reduces the cosmological constant and predicts a transition from acceleration to deceleration in the universe's evolution.

Findings

Effective cosmological constant can match current observations.

Universe will transition from acceleration to deceleration.

Future decelerating phase resolves de Sitter universe problems.

Abstract

Orbifold branes are studied in the framework of the 11-dimensional Horava-Witten heterotic M-Theory. It is found that the effective cosmological constant can be easily lowered to its current observational value by the mechanism of large extra dimensions. The domination of this constant over the evolution of the universe is only temporarily. Due to the interaction of the bulk and the branes, the universe will be in its decelerating expansion phase again in the future, whereby all problems connected with a far future de Sitter universe are resolved.