English

A question of Kuhnau

Complex Variables 2018-08-09 v1

Abstract

It is well known that the square is not a Strebel's point (i.e., its extremal Beltrami coefficient is not Teichmuller). Many years ago, Reiner Kuhnau posed the question: does there exist in the case of a "long" rectangle the corresponding holomorphic quadratic differential? We prove that the answer is negative for any bounded convex quadrilateral and establish a stronger result for rectangles.

Cite

@article{arxiv.1808.02845,
  title  = {A question of Kuhnau},
  author = {Samuel L. Krushkal},
  journal= {arXiv preprint arXiv:1808.02845},
  year   = {2018}
}

Comments

arXiv admin note: text overlap with arXiv:1806.02760

R2 v1 2026-06-23T03:28:03.815Z