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arXiv · 1606.08840

Parabolic Conjugation and Commuting Varieties

Magdalena Boos·Michaël Bulois
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Abstract

We consider the conjugation-action of an arbitrary upper-block parabolic subgroup of the general linear group on the variety of nilpotent matrices in its Lie algebra. Lie-theoretically, it is natural to wonder about the number of orbits of this action. We translate the setup to a representation-theoretic one and obtain a finiteness criterion which classifies all actions with only a finite number of orbits over an arbitrary infinite field. These results are applied to commuting varieties and nested punctual Hilbert schemes.

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Magdalena Boos, Michaël Bulois. 2019-02-27. Parabolic Conjugation and Commuting Varieties. https://arxiv.org/abs/1606.08840

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