Filtrations of Tope Spaces of Oriented Matroids

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Shaw, Kris, Yuen, Chi Ho
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866913120556941312
author Shaw, Kris
Yuen, Chi Ho
author_facet Shaw, Kris
Yuen, Chi Ho
contents We compare three filtrations of the tope space of an oriented matroid. The first is the dual Varchenko-Gelfand degree filtration, the second filtration is from Kalinin's spectral sequence, and the last one derives from Quillen's augmentation filtration. We show that all three filtrations and the respective maps coincide over $\mathbb{Z}/ 2\mathbb{Z}$. We also show that the dual Varchenko-Gelfand degree filtration can be made into a filtration of the $\mathbb{Z}$-sign cosheaf on the fan of the underlying matroid. This was previously carried out with $\mathbb{Z}/ 2\mathbb{Z}$-coefficients by the first author and Renaudineau using the Quillen filtration and has applications to real algebraic geometry via patchworking.
format Preprint
id arxiv_https___arxiv_org_abs_2501_11295
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Filtrations of Tope Spaces of Oriented Matroids
Shaw, Kris
Yuen, Chi Ho
Combinatorics
Algebraic Geometry
Algebraic Topology
52C40, 52C35, 05B35, 14T15
We compare three filtrations of the tope space of an oriented matroid. The first is the dual Varchenko-Gelfand degree filtration, the second filtration is from Kalinin's spectral sequence, and the last one derives from Quillen's augmentation filtration. We show that all three filtrations and the respective maps coincide over $\mathbb{Z}/ 2\mathbb{Z}$. We also show that the dual Varchenko-Gelfand degree filtration can be made into a filtration of the $\mathbb{Z}$-sign cosheaf on the fan of the underlying matroid. This was previously carried out with $\mathbb{Z}/ 2\mathbb{Z}$-coefficients by the first author and Renaudineau using the Quillen filtration and has applications to real algebraic geometry via patchworking.
title Filtrations of Tope Spaces of Oriented Matroids
topic Combinatorics
Algebraic Geometry
Algebraic Topology
52C40, 52C35, 05B35, 14T15
url https://arxiv.org/abs/2501.11295