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Boundary Distortion and the Schwarzian Derivative of a Univalent Function in a Circular Annulus

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Abstract

New distortion theorems are proved for holomorphic univalent functions bounded in a circular annulus and preserving one of its boundary components. In particular, inequalities including the Schwarzian derivative at a boundary point of the annulus are established. All results follow from the properties of the conformal capacity of condensers and symmetrization.

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Notes

  1. See, e.g., [7, Sec. 2.1].

  2. Inequality (1) can also be obtained by using inequality (11) in [6] with a description of all cases of equality.

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Funding

This research was supported by the Mathematical Center in Akademgorodok under agreement no. 075-15-2022-281 of 05.04.2022 with the Ministry of Science and Higher Education of the Russian Federation.

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Correspondence to V. N. Dubinin.

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Translated from Matematicheskie Zametki, 2023, Vol. 113, pp. 827–835 https://doi.org/10.4213/mzm13808.

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Dubinin, V.N. Boundary Distortion and the Schwarzian Derivative of a Univalent Function in a Circular Annulus. Math Notes 113, 776–783 (2023). https://doi.org/10.1134/S000143462305019X

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  • DOI: https://doi.org/10.1134/S000143462305019X

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