The Intermediate Scale Branch of the Landscape

TL;DR

This paper discusses a specific branch of string theory landscape models, highlighting their generic features, phenomenological implications, and potential explanations for the weak scale tuning related to dark matter density.

Contribution

It identifies a class of string landscape models with logarithmic supersymmetry breaking scales and analyzes their generic phenomenological features and tuning mechanisms.

Findings

KKLT models are representative of this landscape branch.

Phenomenology depends on a small set of discrete choices.

Weak scale tuning may be explained by dark matter density selection.

Abstract

Three branches of the string theory landscape have plausibly been identified. One of these branches is expected to exhibit a roughly logarithmic distribution of supersymmetry breaking scales. The original KKLT models are in this class. We argue that certain features of the KKLT model are generic to this branch, and that the resulting phenomenology depends on a small set of discrete choices. As in the MSSM, the weak scale in these theories is tuned; a possible explanation is selection for the dark matter density.