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Department of Mathematics,
University of California San Diego

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Math 208: Seminar in Algebraic Geometry

Dr. Miguel Moreira

Massachusetts Institute of Technology

The Chern filtration on the cohomology of moduli spaces of (parabolic) bundles

Abstract:

The Chern filtration is a natural filtration that can be defined on the cohomology of moduli spaces of sheaves. Its definition was originally made for the moduli of Higgs bundles, motivated by a comparison with the perverse and weight filtrations, but it also makes sense for the very classical moduli spaces of bundles on curves. A vanishing result conjectured by Newstead and proved by Earl-Kirwan in the 90s is secretly a statement about the Chern filtration. I will explain a new approach to this vanishing which is based on parabolic bundles: it turns out that enriching the problem with a parabolic structure gives access to powerful tools, such as wall-crossing, Hecke transforms and Weyl symmetry — together, these give a new proof of the Newstead-Jefrey-Kirwan vanishing and a related "d independence" statement. Part of the talk is based on work with W. Lim and W. Pi.
 

Host: Dragos Oprea

April 25, 2025

4:00 PM

APM 7321

Research Areas

Algebraic Geometry

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