Bruhat order for two flags and a line

dc.creatorMagyar, Peter
dc.date2002-01-11
dc.date2003-10-13
dc.date.accessioned2026-07-07T04:45:49Z
dc.date.available2026-07-07T04:45:49Z
dc.descriptionThe classical Ehresmann-Bruhat order describes the possible degenerations of a pair of flags in a linear space V under linear transformations of V; or equivalently, it describes the closure of an orbit of GL(V) acting diagonally on the product of two flag varieties. We consider the degenerations of a triple consisting of two flags and a line, or equivalently the closure of an orbit of GL(V) acting diagonally on the product of two flag varieties and a projective space. We give a simple rank criterion to decide whether one triple can degenerate to another. We also classify the minimal degenerations, which involve not only reflections (i.e., transpositions) in the Weyl group S_n, n=dim(V), but also cycles of arbitrary length. Our proofs use only elementary linear algebra and combinatorics.
dc.description36 pages. Version 2 adds an Introduction stating results in terms of S_n; and corrects typos, including in statement of move (v). Version 3: typos
dc.identifierhttps://arxiv.org/abs/math/0201104
dc.identifierhttp://arxiv.org/abs/math/0201104
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/63099
dc.subjectRepresentation Theory
dc.subjectAlgebraic Geometry
dc.subjectCombinatorics
dc.subject14L35; 51N30
dc.titleBruhat order for two flags and a line
dc.typetext

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