Stringy World Branes and Exponential Hierarchies

TL;DR

This paper explores string theory realizations of the Randall-Sundrum scenario with supersymmetry, discussing how string duality predicts warp factors and analyzing the challenges of applying RS hierarchy explanations within string theory.

Contribution

It provides heterotic and M-theory models of RS scenarios with supersymmetry, highlighting string duality implications and limitations in explaining hierarchy.

Findings

String duality predicts warp factors in Calabi-Yau compactifications.

Supersymmetry can be broken only on the world brane in these models.

Challenges exist in satisfying RS hierarchy assumptions in string theory.

Abstract

We describe heterotic string and M-theory realizations of the Randall-Sundrum (RS) scenario with $\cx N=2$ and $\cx N=1$ supersymmetry in the bulk. Supersymmetry can be broken only on the world brane, a scenario that has been proposed to account for the smallness of the cosmological constant. An interesting prediction from string duality is the generation of a warp factor for conventional type II Calabi--Yau 3-fold compactifications. On the other hand we argue that an assumption that is needed in the RS explanation of the hierarchy is hard to satisfy in the string theory context.