Uniform density in matroids, matrices and graphs

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Devriendt, Karel, Mulas, Raffaella
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908803366125568
author Devriendt, Karel
Mulas, Raffaella
author_facet Devriendt, Karel
Mulas, Raffaella
contents We give new characterizations for the class of uniformly dense matroids and study applications of these characterizations to graphic and real representable matroids. We show that a matroid is uniformly dense if and only if its base polytope contains a point with constant coordinates. As a main application, we derive new spectral, structural and classification results for uniformly dense graphs. In particular, we show that connected regular uniformly dense graphs are $1$-tough and thus contain a (near-)perfect matching. As a second application, we show that strictly uniformly dense real represented matroids can be represented by projection matrices with a constant diagonal and that they are parametrized by a subvariety of the Grassmannian.
format Preprint
id arxiv_https___arxiv_org_abs_2306_15267
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Uniform density in matroids, matrices and graphs
Devriendt, Karel
Mulas, Raffaella
Combinatorics
Discrete Mathematics
Spectral Theory
We give new characterizations for the class of uniformly dense matroids and study applications of these characterizations to graphic and real representable matroids. We show that a matroid is uniformly dense if and only if its base polytope contains a point with constant coordinates. As a main application, we derive new spectral, structural and classification results for uniformly dense graphs. In particular, we show that connected regular uniformly dense graphs are $1$-tough and thus contain a (near-)perfect matching. As a second application, we show that strictly uniformly dense real represented matroids can be represented by projection matrices with a constant diagonal and that they are parametrized by a subvariety of the Grassmannian.
title Uniform density in matroids, matrices and graphs
topic Combinatorics
Discrete Mathematics
Spectral Theory
url https://arxiv.org/abs/2306.15267