A Stringy Mechanism for A Small Cosmological Constant

TL;DR

This paper proposes a string theory-based mechanism that naturally favors vacua with a small cosmological constant by analyzing probability distributions of products of random variables within flux compactification models.

Contribution

It introduces a simple stringy mechanism based on probability distributions that explains the smallness of the cosmological constant in string theory vacua.

Findings

Probability distributions of functions of random variables often peak at zero.

The mechanism favors meta-stable vacua with small cosmological constants.

In the single modulus model, the suppression of small cosmological constants is modest.

Abstract

Based on the probability distributions of products of random variables, we propose a simple stringy mechanism that prefers the meta-stable vacua with a small cosmological constant. We state some relevant properties of the probability distributions of functions of random variables. We then illustrate the mechanism within the flux compactification models in Type IIB string theory. As a result of the stringy dynamics, we argue that the generic probability distribution for the meta-stable vacua typically peaks with a divergent behavior at the zero value of the cosmological constant. However, its suppression in the single modulus model studied here is modest.