The structure and rigidiy of FBCMC hypersurfaces
Jia Li
TL;DR
This work addresses rigidity of complete stable two-sided free boundary minimal hypersurfaces in 5-manifolds with boundary under curvature constraints, establishing that strict positivity of the $k$-tri-Ricci curvature together with non-negative $3$-intermediate Ricci curvature forces rigidity in manifolds with weakly convex boundary and bounded geometry. The authors extend Wu's 2023 4D results to dimension five and adapt the free boundary μ-bubble framework alongside 3D diameter estimates to control end behavior and volume growth, culminating in a rigidity conclusion: $M$ is totally geodesic, with $\mathrm{Ric}_N(\eta,\eta)=0$ on $M$ and $A_{\partial N}(\eta,\eta)=0$ on $\partial M$, and the end structure is constrained to at most one non-parabolic end. A corollary of the analysis yields nonexistence of complete stable two-sided free boundary minimal hypersurfaces in compact $(N^5,\partial N)$ with positive sectional curvature and weakly convex boundary. Overall, the paper advances free boundary rigidity theory in higher dimensions by combining μ-bubble variational methods with end-structure analysis under sharp curvature conditions.
Abstract
We prove that the combination of strict positivity of $k$-tri-Ricci curvature with non-negative $3$-intermediate Ricci curvature forces rigidity of two-sided stable free boundary minimal hypersurface in a 5-manifold with bounded geometry and weakly convex boundary. This improves the result of Wu \cite{Wuyujie2023} to 5-dimensions and also extends the method of Hong-Yan \cite{Hong-cmc nonexis} to the free boundary case. We give a characterization of one-endedness for weakly stable free boundary constant mean curvature(FBCMC) hypersurfaces, which is an extension of Cheng-Cheung-Zhou \cite{Cheng-Cheung-Zhou2008}.
