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arXiv · 2605.13510

On Ramanujam's Theorem About Finite Dimensional Groups of Automorphisms

Serge Cantat·Hanspeter Kraft·Andriy Regeta·Immanuel van Santen
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Abstract

Ramanujam's theorem states that any connected finite-dimensional subgroup of the automorphism group $\mathrm{Aut}(X)$ of an irreducible variety $X$ is an algebraic group, in a natural way. In this note, we discuss the notion of dimension and extend Ramanujam's theorem to arbitrary (not necessarily irreducible) varieties.

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Serge Cantat, Hanspeter Kraft, Andriy Regeta, Immanuel van Santen. 2026-05-13. On Ramanujam's Theorem About Finite Dimensional Groups of Automorphisms. https://arxiv.org/abs/2605.13510

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