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Normality of Schubert varieties in affine Grassmannians

Algebraic Geometry 2025-07-10 v2 Representation Theory

Abstract

We classify all normal Schubert varieties in the affine Grassmannian of a semisimple group over an arbitrary field with special attention to small positive characteristic. The proof is elementary and relies on tangent space calculations for quasi-minuscule Schubert varieties, a refined Levi lemma in positive characteristic and the classification of minimal degenerations.

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Cite

@article{arxiv.2312.11154,
  title  = {Normality of Schubert varieties in affine Grassmannians},
  author = {Patrick Bieker and Timo Richarz},
  journal= {arXiv preprint arXiv:2312.11154},
  year   = {2025}
}

Comments

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