Towards a Natural Theory of Dark Energy: Supersymmetric Large Extra Dimensions

TL;DR

This paper reviews the naturalness issues in Dark Energy theories and advocates for Supersymmetric Large Extra Dimensions (SLED) as a promising solution, highlighting its current status, tests passed, criticisms, and future experimental predictions.

Contribution

It introduces and evaluates the SLED model as a natural, supersymmetric approach to Dark Energy, addressing key issues and proposing testable predictions.

Findings

SLED survives current experimental tests

Predicts distinctive signatures in cosmology and particle physics

Addresses naturalness problems in Dark Energy theories

Abstract

The first part of this article summarizes the evidence for Dark Energy and Dark Matter, as well as the naturalness issues which plague current theories of Dark Energy. The main point of this part is to argue why these naturalness issues should provide the central theoretical guidance for the search for a successful theory. The second part of the article describes the present status of what I regard as being the best mechanism yet proposed for addressing this issue: Six-dimensional Supergravity with submillimetre-sized Extra Dimensions (Supersymmetric Large Extra Dimensions, or SLED for short). Besides summarizing the SLED proposal itself, this section also describes the tests which this model has passed, the main criticisms which have been raised, and the remaining challenges which remain to be checked. The bottom line is that the proposal survives the tests which have been completed to date, and predicts several distinctive experimental signatures for cosmology, tests of gravity and for accelerator-based particle physics.