Modified Hawking mass and rigidity of three-manifolds with boundary
Jihyeon Lee, Sanghun Lee
TL;DR
The paper proves a local rigidity result for 3-manifolds with boundary under a negative scalar curvature regime by examining a free boundary minimal two-disk that locally maximizes the modified Hawking mass. It develops a variational framework and sharp area estimates linked to the first Jacobi eigenvalue, then constructs a constant-mean-curvature foliation near the disk. Under the assumptions $\inf_{M} R^{M} = -6$ and $\inf_{\partial M} H^{\partial M} = 0$, the authors show the disk has constant Gaussian curvature $K^{\Sigma} = 1/a^{2}$ and vanishing boundary geodesic curvature, and the ambient space is locally isometric to the half anti-de Sitter–Schwarzschild manifold $(g_{hadss})_{a}$. This extends rigidity phenomena to manifolds with boundary in the AdS-like setting and connects quasi-local mass maximization to local geometric realizations in model spaces.
Abstract
In this paper, we prove a rigidity result for three-dimensional Riemannian manifolds with boundary, under the assumption that a free boundary minimal two-disk, which locally maximizes a modified Hawking mass, is embedded in a $3$-dimensional Riemannian manifold with negative scalar curvature and mean convex boundary. First, we establish area estimates for free boundary strictly stable two-disks. Finally, we show that the $3$-dimensional Riemannian manifold with boundary is locally isometric to the half anti-de Sitter-Schwarzschild manifold.
