A Small Cosmological Constant, Grand Unification and Warped Geometry

TL;DR

This paper proposes a mechanism within warped geometry models to naturally generate a small cosmological constant, linking it to the GUT scale, and demonstrates its realization in string theory with realistic particle physics features.

Contribution

It introduces a novel warp-factor suppression mechanism for the cosmological constant and explicitly embeds it in a string-theoretic GUT framework.

Findings

The suppression scale relates to the GUT scale.

The mechanism is demonstrated in a 5D brane-world setup.

The string theory realization yields a realistic MSSM spectrum.

Abstract

We explore a mechanism to obtain the observational small value for the 4-dimensional vacuum energy through an exponential warp-factor suppression. Intriguingly the required suppression scale relates directly to the GUT scale. We demonstrate the mechanism explicitly in a 5-dimensional brane-world setup with warped geometry. Upon lifting the setup to 10-dimensional IIB string-theory, the relevance of the GUT scale becomes clear as the IIB string-theory description, which is based on D3-brane stacks, gives rise to a spontaneously broken SU(5) supersymmetric GUT theory with low-energy MSSM spectrum and Higgs doublet-triplet splitting.