Volume Weighted Measures of Eternal Inflation in the Bousso-Polchinski Landscape

TL;DR

This paper analyzes volume weighted measures of eternal inflation within the Bousso-Polchinski landscape, predicting low energy vacua with specific flux configurations and providing insights into the cosmological constant and coincidence problems.

Contribution

It introduces a volume weighted measure in the Bousso-Polchinski model that predicts observable vacuum properties and offers a potential anthropic solution to the cosmological constant problem.

Findings

Observers likely find themselves in vacua with one dominant flux.

The measure predicts a smooth distribution of Lambda values.

Typical vacua have lifetimes around 12 billion years.

Abstract

We consider the cosmological dynamics associated with volume weighted measures of eternal inflation, in the Bousso-Polchinski model of the string theory landscape. We find that this measure predicts that observers are most likely to find themselves in low energy vacua with one flux considerably larger than the rest. Furthermore, it allows for a satisfactory anthropic explanation of the cosmological constant problem by producing a smooth, and approximately constant, distribution of potentially observable values of Lambda. The low energy vacua selected by this measure are often short lived. If we require anthropically acceptable vacua to have a minimum life-time of 10 billion years, then for reasonable parameters a typical observer should expect their vacuum to have a life-time of approximately 12 billion years. This prediction is model dependent, but may point toward a solution to the coincidence problem of cosmology.