Whitney–Graustein homotopy of locally convex curves via a curvature flow

Abstract

Let $X_0, \tilde{X}$ be two smooth, closed and locally convex curves in the plane with same winding number. A curvature flow with a nonlocal term is constructed to evolve $X_0$ into $\tilde{X}$. It is proved that this flow exits globally, preserves both the local convexity and the elastic energy of the evolving curve. If the two curves have same elastic energy then the curvature flow deforms the evolving curve into the target curve $\tilde{X}$ as time tends to infinity.