Lipschitz homotopies of mappings from 3-sphere to 2-sphere

Abstract

This work focuses on important step in quantitative topology: given homotopic mappings from S^m to S^n of Lipschitz constant L, build the (asymptotically) simplest homotopy between them (meaning having the least Lipschitz constant). The present paper resolves this problem for the first case where Hopf invariant plays a role: m = 3, n = 2, constructing a homotopy with Lipschitz constant O(L).