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arXiv · 2210.01262

Geometric properties of Blaschke-like maps on domains with a conic boundary

Masayo Fujimura·Yasuhiro Gotoh
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Abstract

For a circle $ C $ contained in the unit disk, the necessary and sufficient condition for the existence of a triangle inscribed in the unit circle and circumscribed about $ C $ is known as Chapple's formula. The geometric properties of Blaschke products of degree 3 given by Daepp et al. (2002) and Frantz (2004) allow us to extend Chapple's formula to the case of ellipses in the unit disk. The main aim of this paper is to provide a further extension of Chapple's formula. Introducing a Blaschke-like map of a domain whose boundary is a conic, we extend their results to the case where the outer curve is an ellipse or a parabola. Moreover, we also give some geometrical properties for the Blaschke-like maps of degree $ d $.

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Masayo Fujimura, Yasuhiro Gotoh. 2022-10-03. Geometric properties of Blaschke-like maps on domains with a conic boundary. https://doi.org/10.1007/s40315-023-00499-z

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