A Constrained Mean Curvature Flow On Capillary Hypersurface Supported On Totally Geodesic Plane
Xiaoxiang Chai, Yimin Chen
TL;DR
This work develops a constrained mean curvature flow for capillary hypersurfaces in hyperbolic space $\mathbb H^{n+1}$ supported on a totally geodesic plane, preserving the enclosed volume. It proves a new Minkowski type integral formula for such capillary hypersurfaces, enabling a volume-preserving flow whose scalar equation is derived via a radial function $u$ on $\mathbb S^n_+$; under a sharp angle condition, the flow exists globally and converges to a $\theta$-umbilical cap. Moreover, the authors show that a $\theta$-umbilical cap minimizes the capillary energy $\mathcal Q(\Sigma) = |\Sigma| - \cos\theta |\widehat{\partial\Sigma}|$ among caps with the same enclosed volume. Collectively, these results provide a variational perspective and stability for capillary profiles in hyperbolic space, with implications for geometric inequalities and constructive approaches to energy-minimizing capillary caps.
Abstract
We prove a new Minkowski type formula for capillary hypersurfaces supported on totally geodesic hyperplanes in hyperbolic space. It leads to a volume-preserving flow starting from a star-shaped initial hypersurface. We prove the long-time existence of the flow and its uniform convergence to a $θ$-totally umbilical cap. Additionally, we establish that a $θ$-totally umbilical cap is an energy minimizer for a given enclosed volume.
