Large Schubert varieties

dc.creatorBrion, Michel
dc.creatorPolo, Patrick
dc.date1999-04-26
dc.date.accessioned2026-07-07T05:28:49Z
dc.date.available2026-07-07T05:28:49Z
dc.descriptionFor a semisimple adjoint algebraic group $G$ and a Borel subgroup $B$, consider the double classes $BwB$ in $G$ and their closures in the canonical compactification of $G$: we call these closures large Schubert varieties. We show that these varieties are normal and Cohen-Macaulay; we describe their Picard group and the spaces of sections of their line bundles. As an application, we construct geometrically van der Kallen's filtration of the algebra of regular functions on $B$. We also construct a degeneration of the flag variety $G/B$ embedded diagonally in $G/B\times G/B$, into a union of Schubert varieties. This leads to formulae for the class of the diagonal in $T$-equivariant $K$-theory of $G/B\times G/B$, where $T$ is a maximal torus of $B$.
dc.description33 pages, LaTeX2e
dc.identifierhttps://arxiv.org/abs/math/9904144
dc.identifierhttp://arxiv.org/abs/math/9904144
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/78406
dc.subjectAlgebraic Geometry
dc.subjectRepresentation Theory
dc.subject14M15, 14L30, 20G05, 19E15
dc.titleLarge Schubert varieties
dc.typetext

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