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arXiv · 2103.02254

The exact value of Hausdorff dimension of escaping sets of class B meromorphic functions

Volker Mayer·Mariusz Urbański
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Abstract

We consider the subclass of class ${\mathcal B} $ consisting of meromorphic functions $f:{\mathbb C}\to\hat{\mathbb C}$ for which infinity is not an asymptotic value and whose all poles have orders uniformly bounded from above. This class was introduced in \cite{BwKo2012} and the Hausdorff dimension ${\rm HD}({{\mathcal I} (f)})$ of the set ${{\mathcal I} (f)}$ of all points escaping to infinity under forward iteration of $f$ was estimated therein. In this paper we provide a closed formula for the exact value of ${\rm HD}({{\mathcal I} (f)})$ identifying it with the critical exponent of the natural series introduced in \cite{BwKo2012}. This exponent is very easy to calculate for many concrete functions. In particular, we construct a function from this class which is of infinite order and for which ${\rm HD}({{\mathcal I} (f)})=0$.

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Volker Mayer, Mariusz Urbański. 2021-03-03. The exact value of Hausdorff dimension of escaping sets of class B meromorphic functions. https://arxiv.org/abs/2103.02254

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