Geometry of $B \times B$-orbit closures in equivariant embeddings

dc.creatorHe, Xuhua
dc.creatorThomsen, Jesper Funch
dc.date2005-10-05
dc.date2005-10-14
dc.date.accessioned2026-07-07T06:47:10Z
dc.date.available2026-07-07T06:47:10Z
dc.descriptionLet $X$ denote an equivariant embedding of a connected reductive group $G$ over an algebraically closed field $k$. Let $B$ denote a Borel subgroup of $G$ and let $Z$ denote a $B \times B$-orbit closure in $X$. When the characteristic of $k$ is positive and $X$ is projective we prove that $Z$ is globally $F$-regular. As a consequence, $Z$ is normal and Cohen-Macaulay for arbitrary $X$ and arbitrary characteristics. Moreover, in characteristic zero it follows that $Z$ has rational singularities. This extends earlier results by the second author and M. Brion.
dc.description23 pages, revised version. Minor problem with definition of $\mathcal I$ in Section 5.3 resolved
dc.identifierhttps://arxiv.org/abs/math/0510088
dc.identifierhttp://arxiv.org/abs/math/0510088
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/103567
dc.subjectAlgebraic Geometry
dc.subject14M17, 14L30, 14B05
dc.titleGeometry of $B \times B$-orbit closures in equivariant embeddings
dc.typetext

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