On the reducibility of characteristic varieties

1999/07/28 by Tom Braden, Braden, Tom · 1 citation
Mathematics · #32S60 #Algebraic Geometry (math.AG) #FOS: Mathematics #math.AG #msc:32S60

paper · pdf · doi:10.48550/arxiv.math/9907182

LaTeX, 7 pages

arxiv created 2001/01/29 · arxiv updated 2009/11/30

Abstract

We present a result which can be used for stratifications with conical singularities to deduce that a perverse sheaf (in particular, an intersection homology sheaf) has reducible characteristic variety, given a hypothesis on the monodromy of the vanishing cycles local system of a stratum. We apply it to explain most of the examples currently known where SS(IC(X)) is reducible for X a Schubert variety in a flag variety.

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• Trim resolutions, stringy and Mather classes, and IC characteristic cycles

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