How (not) to prove (un)distortion for diffeomorphisms of one-manifolds
This article addresses the following general question: Given a one-dimensional manifold $M$ and $1 \le r<s \le \infty$, does there exist a $C^s$ orientation preserving compactly supported diffeomorphism of $M$ that is undistorted in the group $\mathrm{Diff}_{c,+}^s(M)$ of such diffeomorphisms while distorted in the big...