Mountain Pass Critical Points of the Volume Constrained Area Functional
Gregory R. Chambers, Jared Marx-Kuo
TL;DR
The paper develops a mountain-pass min-max framework for the volume-constrained perimeter problem, producing smooth almost-embedded hypersurfaces with nonzero constant mean curvature under generic metrics. Central to the approach are the F^{h,f} and E^f functionals, whose variational structure yields volume-preserving critical points via a constrained min-max theory modeled on Mazurwoski–Zhou and its regularity theory. A key technical advance is the path-connectedness of the smooth Cacciopoli-set space in the old-F topology, established through transversality and a carving lemma, which enables robust construction of constrained sweepouts. The results extend the min-max program for isoperimetric-type problems to a volume-constrained setting, providing new existence results for CMC hypersurfaces and linking variational methods with GMT regularity in a constrained-volume context.
Abstract
We construct mountain pass critical points of the perimeter functional on sets of fixed volume. For a generic metric, this gives rise to a smooth almost embedded hypersurface with non-zero constant mean curvature. Our work utilizes recent techniques of Mazurwoski--Zhou \cite{mazurowski2024infinitely}, and a new result on the connectedness of Cacciopoli sets: any two smooth Cacciopoli sets can be connected by an $\mathbf{F}$-continuous map.
