Up-to-constants comparison of Liouville first passage percolation and Liouville quantum gravity

TL;DR

This paper establishes that all subsequential limits of Liouville first passage percolation are nearly bi-Lipschitz equivalent to the original metrics, providing sharp bounds and insights into the metric's behavior in Liouville quantum gravity.

Contribution

It proves near bi-Lipschitz equivalence of all subsequential limits of LFPP to the original metrics, and derives sharp bounds for scaling constants.

Findings

All subsequential limits are nearly bi-Lipschitz equivalent to LFPP metrics.

Bounds for LFPP scaling constants are sharp up to polylogarithmic factors.

Any two subsequential limiting metrics are bi-Lipschitz equivalent.

Abstract

Liouville first passage percolation (LFPP) with parameter $\xi > 0$ is the family of random distance functions $\{D_h^\epsilon\}_{\epsilon >0}$ on the plane obtained by integrating $e^{\xi h_\epsilon}$ along paths, where $\{h_\epsilon\}_{\epsilon >0}$ is a smooth mollification of the planar Gaussian free field. Recent works have shown that for all $\xi > 0$ the LFPP metrics, appropriately re-scaled, admit non-trivial subsequential limiting metrics. In the case when $\xi < \xi_{\mathrm{crit}} \approx 0.41$, it has been shown that the subsequential limit is unique and defines a metric on $\gamma$-Liouville quantum gravity $\gamma = \gamma(\xi) \in (0,2)$. We prove that for all $\xi > 0$, each possible subsequential limiting metric is nearly bi-Lipschitz equivalent to the LFPP metric $D_h^\epsilon$ when $\epsilon$ is small, even if $\epsilon$ does not belong to the appropriate subsequence. Using this result, we obtain bounds for the scaling constants for LFPP which are sharp up to polylogarithmic factors. We also prove that any two subsequential limiting metrics are bi-Lipschitz equivalent. Our results are an input in subsequent work which shows that the subsequential limits of LFPP induce the same topology as the Euclidean metric when $\xi = \xi_{\mathrm{crit}}$. We expect that our results will also have several other uses, e.g., in the proof that the subsequential limit is unique when $\xi \geq \xi_{\mathrm{crit}}$.