Holography and Cheeger constant of asymptotically CMC submanifolds
Samuel Pérez-Ayala, Aaron J. Tyrrell
TL;DR
This work analyzes asymptotically hyperbolic spaces with conformally compact, asymptotically CMC submanifolds to obtain sharp bounds on the Cheeger constant and to connect geometry at infinity with intrinsic/submanifold data. It establishes a universal upper bound on the Cheeger constant in terms of the asymptotic mean curvature and constructs two non-Einstein examples with Cheeger constant $ ext{Ch}=n$ corresponding to positive and negative Yamabe types of the conformal infinity. It also links boundary geometry to global conformal properties by showing that an umbilic boundary characterizes conformally weakly Poincaré--Einstein spaces via vanishing of the third conformal fundamental form, and it introduces an extrinsic conformal invariant obstructing second-order mean-curvature vanishing. In the PE setting, a precise boundary–intrinsic/ extrinsic criterion ties weakly Poincaré--Einstein behavior to vanishing of second and third conformal fundamental forms on the boundary. The paper provides explicit constructions, sharp inequalities, and detailed curvature-expansion machinery (including Fialkow–Gauss relations) that illuminate the interplay between bulk geometry, boundary conformal data, and isoperimetric-type invariants.
Abstract
Let $(M^{n+1},g_+)$ be an asymptotically hyperbolic manifold. We compute the Cheeger constant of conformally compact asymptotically constant mean curvature submanifolds $ ι: Y^{k+1} \to (M^{n+1},g_+)$ with arbitrary codimension. As an application, we provide two classes of examples of $(n+1)$-dimensional asymptotically hyperbolic manifolds with Cheeger constant equal to $n$, whose conformal infinity is of the following types: 1) positive Yamabe invariant, and 2) negative Yamabe invariant. Moreover, in the same spirit as Blitz--Gover--Waldron \cite{BlitzSamuel2021CFFa}, we show that an asymptotically hyperbolic manifold with umbilic boundary is conformally weakly Poincaré--Einstein if and only if the third conformal fundamental form of the boundary vanishes. Next, in the space of asymptotically minimal hypersurfaces $Y$ within a Poincaré--Einstein manifold, we identify an extrinsic conformal invariant of $\partial Y$ which obstructs the vanishing of the mean curvature of $Y$ to second order. This conformal invariant is a linear combination of two Riemannian hypersurface invariants of $\partial Y,$ one which depends on its extrinsic geometry within $\overline{Y}$ and the other on its extrinsic geometry within $\partial M;$ neither of which are conformal invariants individually. Finally, we show that for asymptotically minimal hypersurfaces with mean curvature vanishing to second order inside of a Poincaré--Einstein space, being weakly Poincaré--Einstein is equivalent to the boundary of $Y$ having vanishing second and third conformal fundamental forms when viewed as a hypersurface within the conformal infinity.
