Liouville quantum gravity and the Brownian map I: The QLE(8/3,0) metric

TL;DR

This paper constructs a metric on a Liouville quantum gravity sphere with parameter b3=8/3, using quantum Loewner evolution, and begins to unify it with the Brownian map by showing their structures can be aligned.

Contribution

It introduces a method to endow a b3=8/3-LQG sphere with a metric using QLE, bridging the gap between LQG and the Brownian map.

Findings

Constructed a metric on a dense subset of the LQG sphere.

Established properties of the metric consistent with the Brownian map.

Laid groundwork for extending the metric to the entire surface.

Abstract

Liouville quantum gravity (LQG) and the Brownian map (TBM) are two distinct models of measure-endowed random surfaces. LQG is defined in terms of a real parameter $\gamma$, and it has long been believed that when $\gamma = \sqrt{8/3}$, the LQG sphere should be equivalent (in some sense) to TBM. However, the LQG sphere comes equipped with a conformal structure, and TBM comes equipped with a metric space structure, and endowing either one with the other's structure has been an open problem for some time. This paper is the first in a three-part series that unifies LQG and TBM by endowing each object with the other's structure and showing that the resulting laws agree. The present work uses a form of the quantum Loewner evolution (QLE) to construct a metric on a dense subset of a $\sqrt{8/3}$-LQG sphere and to establish certain facts about the law of this metric, which are in agreement with similar facts known for TBM. The subsequent papers will show that this metric extends uniquely and continuously to the entire $\sqrt{8/3}$-LQG surface and that the resulting measure-endowed metric space is TBM.