Dark Energy: fiction or reality?

TL;DR

This paper reviews the interpretation of dark energy, arguing that the cosmological constant is the only viable explanation for cosmic acceleration based on Einstein's equations and Ockham's razor.

Contribution

It provides a clear dimensional analysis and review of the mainstream view that supports the cosmological constant as the source of cosmic acceleration.

Findings

Dimensional analysis supports the cosmological constant as the source of acceleration.

Ockham's razor favors the cosmological constant over alternative dark energy models.

The geometrical nature of Lambda is the most viable explanation for cosmic acceleration.

Abstract

Is Dark Energy justified as an alternative to the cosmological constant $\Lambda$ in order to explain the acceleration of the cosmic expansion ? It turns out that a straightforward dimensional analysis of Einstein equation provides us with clear evidences that the geometrical nature of $\Lambda$ is the only viable source to this phenomenon, in addition of the application of Ockham's razor principle. This contribution is primarily a review of the main stream in the interpretation of $\Lambda$ because it is at the origin of such a research program.