Parabolic bundles and the intersection cohomology of moduli spaces of vector bundles on curves

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Felisetti, Camilla, Szenes, Andras, Trapeznikova, Olga
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866912420368220160
author Felisetti, Camilla
Szenes, Andras
Trapeznikova, Olga
author_facet Felisetti, Camilla
Szenes, Andras
Trapeznikova, Olga
contents The study of the intersection cohomology of moduli spaces of semistable bundles was initiated by Frances Kirwan in the 1980's. In this paper, we give a complete geometric proof of a recursive formula, which reduces the calculation of the intersection Betti numbers of the moduli spaces of semistable bundles on Riemann surfaces in degree-0 and arbitrary rank to the known formulas of the Betti numbers of the smooth, degree-1 moduli spaces. Our formula was motivated by the work of Mozgovoy and Reineke from 2015, and appears as a consequence of the Decomposition Theorem applied to the forgetful map from a parabolic moduli space. We give a detailed description of the topology of this map, and that of the relevant local systems. Our work is self-contained, geometric and focuses on using the multiplicative structures of the theory.
format Preprint
id arxiv_https___arxiv_org_abs_2502_20327
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Parabolic bundles and the intersection cohomology of moduli spaces of vector bundles on curves
Felisetti, Camilla
Szenes, Andras
Trapeznikova, Olga
Algebraic Geometry
14D20
The study of the intersection cohomology of moduli spaces of semistable bundles was initiated by Frances Kirwan in the 1980's. In this paper, we give a complete geometric proof of a recursive formula, which reduces the calculation of the intersection Betti numbers of the moduli spaces of semistable bundles on Riemann surfaces in degree-0 and arbitrary rank to the known formulas of the Betti numbers of the smooth, degree-1 moduli spaces. Our formula was motivated by the work of Mozgovoy and Reineke from 2015, and appears as a consequence of the Decomposition Theorem applied to the forgetful map from a parabolic moduli space. We give a detailed description of the topology of this map, and that of the relevant local systems. Our work is self-contained, geometric and focuses on using the multiplicative structures of the theory.
title Parabolic bundles and the intersection cohomology of moduli spaces of vector bundles on curves
topic Algebraic Geometry
14D20
url https://arxiv.org/abs/2502.20327