English

Polishability of some groups of interval and circle diffeomorphisms

Group Theory 2017-10-31 v2

Abstract

Let M=IM=I or M=S1M=\mathbb{S}^1 and let k1k\geq 1. We exhibit a new infinite class of Polish groups by showing that each group Diff+k+AC(M)\mathop{\rm Diff}_+^{k+AC}(M), consisting of those CkC^k diffeomorphisms whose kk-th derivative is absolutely continuous, admits a natural Polish group topology which refines the subspace topology inherited from Diff+k(M)\mathop{\rm Diff}_+^k(M). By contrast, the group Diff+1+BV(M)\mathop{\rm Diff}_+^{1+BV}(M), consisting of C1C^1 diffeomorphisms whose derivative has bounded variation, admits no Polish group topology whatsoever.

Keywords

Cite

@article{arxiv.1709.04523,
  title  = {Polishability of some groups of interval and circle diffeomorphisms},
  author = {Michael P. Cohen},
  journal= {arXiv preprint arXiv:1709.04523},
  year   = {2017}
}