Generating Small Numbers by Tunneling in Multi-Throat Compactifications

TL;DR

The paper proposes a mechanism in string theory where tunneling between multiple brane throats naturally generates small physical numbers, with implications for the hierarchy problem and dark matter longevity.

Contribution

It introduces a novel tunneling-based mechanism in multi-throat compactifications that explains small numbers and long-lived particles, expanding on previous models.

Findings

Tunneling suppression leads to weak interactions between different branes.

Large supersymmetry breaking in one throat induces TeV-scale SUSY-breaking in another.

Long-lived particles can decay within a Hubble time, affecting dark matter models.

Abstract

A generic F-theory compactification containing many D3 branes develops multiple brane throats. The interaction of observers residing inside different throats involves tunneling suppression and, as a result, is very weak. This suggests a new mechanism for generating small numbers in Nature. One application is to the hierarchy problem: large supersymmetry breaking near the unification scale inside a shallow throat causes TeV-scale SUSY-breaking inside the standard-model throat. Another application, inspired by nuclear-decay, is in designing naturally long-lived particles: a cold dark matter particle residing near the standard model brane decays to an approximate CFT-state of a longer throat within a Hubble time. This suggests that most of the mass of the universe today could consist of CFT-matter and may soften structure formation at sub-galactic scales. The tunneling calculation demonstrates that the coupling between two throats is dominated by higher dimensional modes and consequently is much larger than a naive application of holography might suggest.