The equivariant cohomology ring of the representation variety $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C}))$

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Gritschacher, Simon
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866909981595402240
author Gritschacher, Simon
author_facet Gritschacher, Simon
contents We give a presentation of the $\mathrm{GL}_n(\mathbb{C})$-equivariant cohomology ring with $\mathbb{Z}$-coefficients of the variety $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C})) \subseteq \mathrm{GL}_n(\mathbb{C})^2$ for any $n$. It is torsion free and minimally generated as a $H^\ast B\mathrm{GL}_n(\mathbb{C})$-algebra by $3n$ elements. The ideal of relations is the saturation of an $n$-generator ideal by even powers of the Vandermonde polynomial. For coefficients in a field whose characteristic does not divide $n!$, we also give a presentation of the non-equivariant cohomology ring of $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C}))$.
format Preprint
id arxiv_https___arxiv_org_abs_2601_00683
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The equivariant cohomology ring of the representation variety $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C}))$
Gritschacher, Simon
Algebraic Topology
58D27, 55N91, 55N45
We give a presentation of the $\mathrm{GL}_n(\mathbb{C})$-equivariant cohomology ring with $\mathbb{Z}$-coefficients of the variety $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C})) \subseteq \mathrm{GL}_n(\mathbb{C})^2$ for any $n$. It is torsion free and minimally generated as a $H^\ast B\mathrm{GL}_n(\mathbb{C})$-algebra by $3n$ elements. The ideal of relations is the saturation of an $n$-generator ideal by even powers of the Vandermonde polynomial. For coefficients in a field whose characteristic does not divide $n!$, we also give a presentation of the non-equivariant cohomology ring of $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C}))$.
title The equivariant cohomology ring of the representation variety $\mathrm{Hom}(\mathbb{Z}^2,\mathrm{GL}_n(\mathbb{C}))$
topic Algebraic Topology
58D27, 55N91, 55N45
url https://arxiv.org/abs/2601.00683