Sharp $C^{1,\bar1}$ estimates in Kähler quantization and non-pluripolar Radon measures
Zbigniew Błocki, Tamás Darvas
TL;DR
This work develops sharp on-diagonal $C^{1,\bar{1}}$ estimates for Bergman metrics in Kähler quantization, connecting $i\partial\bar{\partial}\log K^k_\varphi$ to bounds on $i\partial\bar{\partial}\varphi$ and proving $C^{1,\alpha}$ convergence of the quantized potentials $P^k_\varphi$ to $\varphi$ under degenerate but controlled curvature. It leverages both local and global (Kähler) Bergman kernel comparisons, together with Berndtsson’s quantized comparison principle, to derive explicit bounds for local and global Bergman kernels and their derivatives. The authors extend the quantization program beyond smooth or continuous potentials to full mass and finite-energy settings, proving weak convergence of quantum measures $M^k_\varphi$ to the Monge–Ampère measure $\omega_\varphi^n$ and, crucially, to non-pluripolar Radon measures via a broad envelope/perturbation framework. They also develop the Monge–Ampère energy quantization, showing that $I_k(H^k_\varphi)$ converges to $I(\varphi)$ and that perturbations by smooth functions are reflected at the quantum level, linking variational energy principles across the quantum-classical divide. Overall, the results significantly broaden the scope of Kähler quantization to degenerate and singular settings with concrete, optimal estimates and convergence statements.
Abstract
Let $K_\varphi$ denote the weighted Bergman kernel associated to a plurisubharmonic function $\varphi$. We obtain upper bounds and positive lower bounds for the Bergman metric $i\partial \bar{\partial} \log K_\varphi$, expressed solely in terms of upper bounds and positive lower bounds of $i\partial \bar{\partial}\varphi$. Our approach applies in both local and compact Kähler settings. As an immediate application we obtain the optimal $C^{1,α}$-convergence for the quantization of Kähler currents with bounded coefficients. We also show that any non-pluripolar Radon measure on a compact Kähler manifold admits a quantization.
