English

Convexity estimates for hypersurfaces moving by concave curvature functions

Differential Geometry 2020-07-16 v1

Abstract

We study fully nonlinear geometric flows that deform strictly kk-convex hypersurfaces in Euclidean space with pointwise normal speed given by a concave function of the principal curvatures. Specifically, the speeds we consider are obtained by performing a nonlinear interpolation between the mean and the kk-harmonic mean of the principal curvatures. Our main result is a convexity estimate showing that, on compact solutions, regions of high curvature are approximately convex. In contrast to the mean curvature flow, the fully nonlinear flows considered here preserve kk-convexity in a Riemannian background, and we show that the convexity estimate carries over to this setting as long as the ambient curvature satisfies a natural pinching condition.

Keywords

Cite

@article{arxiv.2007.07791,
  title  = {Convexity estimates for hypersurfaces moving by concave curvature functions},
  author = {Stephen Lynch},
  journal= {arXiv preprint arXiv:2007.07791},
  year   = {2020}
}
R2 v1 2026-06-23T17:08:38.791Z