Abstract
We show that the smallest maximal dilatation for a quasiconformal extension of a quasisymmetric function of the unit circle may be larger than indicated by the change in the module of the quadrilaterals with vertices on the circle.
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The research of the second author has been partially supported by the Alfred P. Sloan Foundation and by the U.S. National Science Foundation grant DMS 94-00999.
This research was completed while the first author was visiting the University of Illinois at Urbana-Champaign. He wishes to thank the Department of Mathematics for its kind hospitality.
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Anderson, J.M., Hinkkanen, A. Quadrilaterals and extremal quasiconformal extensions. Commentarii Mathematici Helvetici 70, 455–474 (1995). https://doi.org/10.1007/BF02566018
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DOI: https://doi.org/10.1007/BF02566018