On non-local almost minimal sets and an application to the non-local Massari's Problem
Serena Dipierro, Enrico Valdinoci, Riccardo Villa
TL;DR
This work develops a non-local regularity theory for almost minimal sets with respect to the $s$-perimeter, establishing Hölder regularity, a monotonicity formula, and a tangent-cone analysis that yields a sharp bound on the singular set's Hausdorff dimension ($\dim_{\\\\ ext{H}} \Sigma_E \leq n-3$). It also elucidates stickiness phenomena, showing that almost-minimality is stable under external perturbations and that both sticking and non-sticking configurations can arise, including intermediate behaviors. The theory is then applied to a non-local Massari's Problem, proving existence of minimizers for prescribed non-local mean curvature with $H\in L^\infty$ and deriving $C^{1,\alpha}$ regularity of the boundary. Overall, the paper connects fractional perimeter variational problems to practical non-local curvature prescriptions, providing rigorous regularity and structural results with broad implications for non-local capillarity and obstacle-type problems.
Abstract
We consider a fractional Plateau's problem dealing with sets with prescribed non-local mean curvature. This problem can be seen as a non-local counterpart of the classical Massari's Problem. We obtain existence and regularity results, relying on a suitable version of the non-local theory for almost minimal sets. In this framework, the fractional curvature term in the energy functional can be interpreted as a perturbation of the fractional perimeter. In addition, we also discuss stickiness phenomena for non-local almost minimal sets.
