Distances between homotopy classes of $W^{s,p}({\mathbb{S}}^N;{\mathbb{S}}^N)$

Haim Brezis, Petru Mironescu, Itai Shafrir

We introduce an equivalence relation on $W^{s,p}({\mathbb{S}}^N;{\mathbb{S}}^N)$ involving the topological degree, and we evaluate the distances (in the usual sense and in the Hausdo…