Convergence of the volume preserving fractional mean curvature flow for convex sets
Vesa Julin, Domenico Angelo La Manna
TL;DR
The paper proves that the volume-preserving fractional mean curvature flow for convex initial sets remains smooth for all time and converges exponentially to a ball. It achieves this by first obtaining uniform $C^{1+s}$-regularity from convexity-based curvature bounds, then deriving a height-function formulation and upgrading regularity to $C^{2+s+\alpha}$ via sphere-adapted parabolic Schauder estimates. The key technical advance is a robust $C^{2+\alpha}$ regularity step for the flow that does not rely on convexity for the final stage and leverages a quasilinear formulation of the differentiated flow. Consequently, the flow does not develop singularities and, by existing results, converges exponentially fast to a translated ball, extending Huisken-type convergence to a nonlocal, fractional setting with a solid regularity framework.
Abstract
We prove that the volume preserving fractional mean curvature flow starting from a convex set does not develop singularities along the flow. By the recent result of Cesaroni-Novaga \cite{CN} this then implies that the flow converges to a ball exponentially fast. In the proof we show that the apriori estimates due to Cinti-Sinestrari-Valdinoci \cite{CSV2} imply the $C^{1+α}$-regularity of the flow and then provide a regularity argument which improves this into $C^{2+α}$-regularity of the flow. The regularity step from $C^{1+α}$ into $C^{2+α}$ does not rely on convexity and can probably be adopted to more general setting.
