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arXiv · 2606.22199

A Converse Mean-Value Property

Matěj Moravík·El Hassan Youssfi
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Abstract

We prove a converse mean-value theorem for harmonic functions associated with the invariant Laplace--Beltrami operator on the real unit ball. Under suitable integrability and topological assumptions on the domain and its Green potential, we show that the invariant volume mean-value property characterizes hyperbolic balls centered at the origin. As a consequence, we also answer a question left open by Bruna and D\'etraz in the setting of invariantly harmonic functions.

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Matěj Moravík, El Hassan Youssfi. 2026-06-20. A Converse Mean-Value Property. https://arxiv.org/abs/2606.22199

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