• Title/Summary/Keyword: uniform local univalence

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LINEARLY INVARIANT FUNCTIONS

  • Song, Tai-Sung
    • Communications of the Korean Mathematical Society
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    • v.10 no.4
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    • pp.867-874
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    • 1995
  • Linear invariance is closely related to the concept of uniform local univalence. We give a geometric proof that a holomorphic locally univalent function defined on the open unit disk is linearly invariant if and only if it is uniformly locally univalent.

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UNIFORMLY LOCALLY UNIVALENT FUNCTIONS

  • Song, Tai-Sung
    • The Pure and Applied Mathematics
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    • v.6 no.2
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    • pp.87-93
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    • 1999
  • A holomorphic function f on D = {z : │z│ < 1} is called uniformly locally univalent if there exists a positive constant $\rho$ such that f is univalent in every hyperbolic disk of hyperbolic radius $\rho$. We establish a characterization of uniformly locally univalent functions and investigate uniform local univalence of holomorphic universal covering projections.

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MONOTONICITY OF EUCLIDEAN CURVATURE UNDER LOCALLY UNIVALENT FUNCTIONS

  • Song, Tai-Sung
    • East Asian mathematical journal
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    • v.17 no.2
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    • pp.303-308
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    • 2001
  • Let K($z,\gamma$) denote the euclidean curvature of the curve $\gamma$ at the point z. Flinn and Osgood proved that if f is a univalent mapping of the open unit disk D={z:|z|<1} into itself with f(0)=0 and |f'(0)|<1, then $K(0,\gamma){\leq}K(0,f\;o\;\gamma)$ for any $C^2$ curve $\gamma$ on D through the origin with $K(0,\gamma){\geq}4$. In this paper we establish a generalization of the Flinn-Osgood Monotonicity Theorem.

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