A Heintze-Karcher type inequality in hyperbolic space
Yingxiang Hu, Yong Wei, Tailong Zhou
TL;DR
This work extends the Heintze–Karcher framework to hyperbolic space by proving a shifted inequality for hypersurfaces with $H>n$, namely $\int_{\Sigma} \frac{V-V_{,\nu}}{H-n} d\mu \ge \frac{n+1}{n} \int_{\Omega} V dvol$, with equality characterizing umbilicity. The proof uses the unit normal flow in $\mathbb{H}^{n+1}$ and a monotone functional $Q(t)$ tied to level-set geometry, together with Minkowski-type identities and a limiting argument. The results yield an Alexandrov-type rigidity for hypersurfaces with constant shifted $k$th mean curvature and a uniqueness statement for $h$-convex domains under curvature equations $E_k(\tilde{\kappa})=\chi(V-V_{,\nu})$, thereby advancing rigidity and uniqueness theory in horospherically convex hyperbolic geometry. Overall, the paper generalizes a classical Euclidean inequality to a hyperbolic setting and clarifies the geometric implications for shifted curvature invariants.
Abstract
In this paper, we prove a new Heintze-Karcher type inequality for shifted mean convex hypersurfaces in hyperbolic space. As applications, we prove an Alexandrov type theorem for closed embedded hypersurfaces with constant shifted $k$th mean curvature in hyperbolic space. Furthermore, a uniqueness result for $h$-convex hypersurfaces satisfying certain curvature equations is obtained.
