An existence theorem for sliding minimal sets
Guy David, Camille Labourie
TL;DR
This work proves an existence theorem for the sliding boundary variant of the Plateau problem for $2$-dimensional sets in $\mathbb{R}^n$, under the assumption that the boundary $\Gamma$ is a finite union of $C^{1+\alpha}$ curves with good access to the complement of its convex hull. The authors construct a minimizer by analyzing a minimizing sequence, passing to a weak limit of the associated Hausdorff measures to obtain a sliding minimal limit $E_\infty$, and then building intrinsic Lipschitz retractions onto $E_\infty$ to recover a minimizer in the original class ${\cal E}(E_0,\Gamma)$. The approach hinges on boundary regularity for sliding almost minimal sets (via Dvv) and stability results for limits of such sets (via La), together with a detailed blow-up analysis and a gluing procedure for retractions. The framework also accommodates variants with different functionals and boundary geometries, and yields local biLipschitz parameterizations of certain almost minimal configurations, highlighting the interplay between geometric measure theory, regularity, and variational methods in sliding boundary problems.
Abstract
We prove an existence theorem for the sliding boundary variant of the Plateau problem for $2$-dimensional sets in $\mathbb{R}^n$. The simplest case of sufficient condition is when $n=3$ and the boundary $Γ$ is a finite disjoint union of smooth closed curves contained in the boundary of a convex body, but the main point of our sufficient condition is to prevent the limits in measure of a minimizing sequence to have singularities of type $\mathbb{Y}$ along $Γ$.
