Katz's middle convolution algorithm

dc.creatorSimpson, Carlos T.
dc.date2006-10-17
dc.date2006-10-25
dc.date.accessioned2026-07-07T07:29:09Z
dc.date.available2026-07-07T07:29:09Z
dc.descriptionThis is an expository account of Katz's middle convolution operation on local systems over ${\bf P}^1-\{q\_1,..., q\_n\}$. We describe the Betti and de Rham versions, and point out that they give isomorphisms between different moduli spaces of local systems, following Völklein, Dettweiler-Reiter, Haraoka-Yokoyama. Kostov's program for applying the Katz algorithm is to say that in the range where middle convolution no longer reduces the rank, one should give a direct construction of local systems. This has been done by Kostov and Crawley-Boevey. We describe here an alternative construction using the notion of cyclotomic harmonic bundles: these are like variations of Hodge structure except that the Hodge decomposition can go around in a circle.
dc.descriptionSubmitted to Pure and Applied Math Quarterly, Hirzebruch issue. v2 corrects some history and adds references
dc.identifierhttps://arxiv.org/abs/math/0610526
dc.identifierhttp://arxiv.org/abs/math/0610526
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/117995
dc.subjectAlgebraic Geometry
dc.titleKatz's middle convolution algorithm
dc.typetext

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