摘要
Given a quasisymmetric homeomorphismh of the unit circle onto itself, denote byK n * ,H h andK h the extremal maximal dilatation, boundary dilatation and maximal dilatation ofh, respectively. It is proved that there exists a family of quasisymmetric homeomorphismsh such thatK h <H h =K h * This gives a negative answer to a problem asked independently by Wu and Yang. Furthermore, some related topics are also discussed.
Given a quasisymmetric homeomorphism h of the unit circle onto itself, denote by Kh* , Hh and Kh the extremal maximal dilatation, boundary dilatation and maximal dilatation of h, respectively. It is proved that there exists a family of quasisymmetric homeomoiphisms h such that Kh < Hh = Kh* . This gives a negative answer to a problem asked independently by Wu and Yang. Furthermore, some related topics are also discussed.
