Critical Liouville quantum gravity and CLE$_4$

Abstract: Consider a critical ($\gamma=2$) Liouville quantum gravity (LQG) disk together with an independent conformal loop ensemble (CLE) with parameter $\kappa=4$. We show that the critical LQG surfaces parametrized by the regions enclosed by the CLE$_4$ loops are conditionally independent critical LQG disks given the LQG lengths of the loops. We also show that the joint law of the LQG lengths of the loops is described in terms of the jumps of a certain $3/2$-stable process. Our proofs are via a limiting argument based on the analogous statements for $\gamma \in (\sqrt{8/3},2)$ and $\kappa = \gamma^2 \in (8/3,4)$ which were proven by Miller, Sheffield, and Werner (2020). Our results are used in the construction of a coupling of supercritical LQG with CLE$_4$ in another paper by the same authors.