The dark dimension, proton decay, and the length of the M-theory interval

Abstract

The existence of a large extra dimension in which only gravity propagates would have spectacular consequences for cosmology and laboratory experiments. In the strong coupling limit of the $E_8\times E_8$ heterotic string theory, the gauge and matter fields live at the end of the eleventh dimension, which becomes a natural candidate for a micron-size \textit{dark dimension}. In this work, however, we show that the length of the M-theory interval is severely constrained by proton decay searches. Our results indicate that in such constructions the size of the eleventh dimension is $R\lesssim \mathcal{O}(10^{-28})$ meters.

9 pages, 1 figure, 7 small dimensions - Published version (new section discussing M5 branes in the bulk)

References in corpus (12)

• On the Geometry of the String Landscape and the Swampland
• GUTs and Exceptional Branes in F-theory - II: Experimental Predictions
• Black Hole Bound on the Number of Species and Quantum Gravity at LHC
• Four-Dimensional SCFTs from M5-Branes
• The Dark Dimension and the Swampland
• Fibrations in CICY Threefolds
• Proton decay via dimension-six operators in intersecting D6-brane models
• The Dark Dimension in a Warped Throat
• A Heterotic Standard Model with B-L Symmetry and a Stable Proton
• Six-dimensional Origin of $\mathcal{N}=4$ SYM with Duality Defects
• The Standard Model from String Theory: What Have We Learned?
• Extremal Bundles on Calabi-Yau Threefolds