English

Higher degree obstructions to quasiconformal equivalence

Metric Geometry 2026-07-13 v1

Abstract

Pairs of diffeomorphic Riemannian manifolds are shown not to be quasiconformally equivalent, while no degree one invariant (extremal lengths, conformal parabolicity,...) can distinguish them. The obstruction arises from conformal cohomology in degree 2. Similar examples are constructed in the contact subRiemannian category

Cite

@article{arxiv.2607.11331,
  title  = {Higher degree obstructions to quasiconformal equivalence},
  author = {Pierre Pansu and Francesca Tripaldi},
  journal= {arXiv preprint arXiv:2607.11331},
  year   = {2026}
}