Chinese Science Bulletin

, 45:313 | Cite as

A class of quasisymmetric mappings with substantial points

  • Zhong Li
  • Shengjian Wu
  • Yi Qi


It is proved thatK q (h)=K 0(h) for everyh in some class of quasisymmetric mappings of the unit circle with substantial points, whereK q (h):=sup{M(h(Q))/M(Q);Q is a quadrilateral with the domain unit disk} andK 0(h) is the extremal maximum dilatation ofh.


quasisymmetric mapping extremal mapping substantial point 


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Copyright information

© Science in China Press 2000

Authors and Affiliations

  • Zhong Li
    • 1
  • Shengjian Wu
    • 1
  • Yi Qi
    • 1
  1. 1.School of Mathematical SciencesPeking UniversityBeijingChina

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