On Ramanujam's Theorem About Finite Dimensional Groups of Automorphisms
Algebraic Geometry
2026-05-15 v1 Group Theory
Abstract
Ramanujam's theorem states that any connected finite-dimensional subgroup of the automorphism group of an irreducible variety 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.
Cite
@article{arxiv.2605.13510,
title = {On Ramanujam's Theorem About Finite Dimensional Groups of Automorphisms},
author = {Serge Cantat and Hanspeter Kraft and Andriy Regeta and Immanuel van Santen},
journal= {arXiv preprint arXiv:2605.13510},
year = {2026}
}
Comments
11 pages, comments welcome!