Minimality of free-boundary axial hyperplanes in high dimensional circular cones via calibration
Giacomo Vianello
TL;DR
This work addresses the free-boundary minimality of axial hyperplanes in high-dimensional circular cones. It develops a calibration framework adapted to boundary-tangent conditions, constructing a divergence-free vector field $Z$ (via a two-step process that first yields a boundary calibration $Y$ and then extends by vertical projection) to compare the relative perimeters of a minimizer $E$ with competing sets. The main result shows that for $n\ge 4$ and $0<\lambda\le\bar{\lambda}(n)$, the axial half-space $E=\{(x,t): x_1>0\}$ minimizes the relative perimeter in the cone $\Omega_{\lambda}$, providing a higher-dimensional counterexample to Vertex-skipping type results. These findings illuminate the boundary regularity and stability aspects of free-boundary minimal surfaces in cones and highlight a dimension-dependent transition in behavior as $n$ increases.
Abstract
Consider an $(n+1)$-dimensional circular cone. Using a calibration argument, we prove that if $n \geq 4$ and the aperture of the cone is sufficiently large, the intersection of the cone with an axial hyperplane is area-minimizing with respect to free-boundary variations inside the cone.
