Calabi flow with bounded $L^p$ scalar curvature (II)
Haozhao Li, Linwei Zhang
TL;DR
The paper proves that the Calabi flow on a compact Kähler manifold can be extended beyond a finite time provided a space-time $L^p$-type bound on the scalar curvature and its Laplacian holds with $p>n$. It leverages the parabolic structure of the flow to establish a sequence of a priori estimates, starting with L∞ control of the potential and the auxiliary function $F$, then obtaining space-time $L^s$ bounds for $n+\Delta_g\varphi$ and gradient bounds for $\nabla F$ and $\nabla\varphi$, and finally bounding $\|n+\Delta_g\varphi\|_{\infty}$. These bounds feed into parabolic Hölder regularity for $F$ and $\varphi$, enabling an extension past $T$ via a standard continuation argument. The results connect Calabi flow extension criteria to analogous results for Ricci and mean curvature flows, highlighting the role of space-time curvature control in fourth-order geometric flows. The techniques combine Chen-Cheng parabolic estimates with parabolic Moser iteration and parabolic Sobolev inequalities on evolving Kähler metrics to achieve a comprehensive a priori estimate framework.
Abstract
In this paper, we show that on a compact Kähler manifold the Calabi flow can be extended as long as some space-time $L^p$ integrals of the scalar curvature are bounded.
