Landscape Predictions from Cosmological Vacuum Selection

TL;DR

This paper analyzes how cosmological dynamics influence the distribution of vacua in string theory landscapes, revealing that evolution narrows the range of accessible vacua and yields specific predictions without the measure problem.

Contribution

It introduces a holographic measure approach to study landscape vacuum probabilities, showing cosmological evolution constrains vacua selection and avoids the measure problem.

Findings

Most fluxes are driven into narrow value ranges by cosmological dynamics

Only a tiny fraction of vacua with small cosmological constant are accessible

The holographic measure avoids the measure problem in eternal inflation

Abstract

In BP models with hundreds of fluxes, we compute the effects of cosmological dynamics on the probability distribution of landscape vacua. Starting from generic initial conditions, we find that most fluxes are dynamically driven into a different and much narrower range of values than expected from landscape statistics alone. Hence, cosmological evolution will access only a tiny fraction of the vacua with small cosmological constant. This leads to a host of sharp predictions. Unlike other approaches to eternal inflation, the holographic measure employed here does not lead to "staggering", an excessive spread of probabilities that would doom the string landscape as a solution to the cosmological constant problem.