The Emergence Proposal and the Emergent String

TL;DR

This paper investigates the Emergence Proposal within a specific string compactification model, demonstrating how light particle towers and an emergent string influence the moduli space and gauge couplings, revealing new insights into the emergence mechanism.

Contribution

It provides a detailed analysis of the emergence mechanism in a concrete string theory model, highlighting the roles of KK modes, winding modes, and an emergent string in shaping the moduli dependence.

Findings

KK and winding modes determine classical moduli dependence

Emergent string causes moduli-dependent logarithmic suppressions

Identifies issues with species scale definition in string tower contexts

Abstract

We explore the Emergence Proposal for the moduli metric and the gauge couplings in a concrete model with 7 saxionic and 7 axionic moduli fields, namely the compactification of the type IIA superstring on a 6-dimensional toroidal orbifold. We show that consistency requires integrating out precisely the 12 towers of light particle species arising from KK and string/brane winding modes and one asymptotically tensionless string up to the species scale. After pointing out an issue with the correct definition of the species scale in the presence of string towers, we carry out the emergence computation and find that the KK and winding modes indeed impose the classical moduli dependence on the one-loop corrections, while the emergent string induces moduli dependent logarithmic suppressions. The interpretation of these results for the Emergence Proposal are discussed revealing a couple of new and still not completely settled aspects.