Campus Units

Mathematics

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

6-2012

Journal or Book Title

Linear Algebra and its Applications

Volume

436

First Page

4373

Last Page

4391

DOI

10.1016/j.laa.2010.12.024

Abstract

The minimum rank of a graph has been an interesting and well studied parameter investigated by many researchers over the past decade or so. One of the many unresolved questions on this topic is the so-called graph complement conjecture, which grew out of a workshop in 2006. This conjecture asks for an upper bound on the sum of the minimum rank of a graph and the minimum rank of its complement, and may be classified as a Nordhaus–Gaddum type problem involving the graph parameter minimum rank. The conjectured bound is the order of the graph plus two. Other variants of the graph complement conjecture are introduced here for the minimum semidefinite rank and the Colin de Verdière type parameter ν. We show that if the ν-graph complement conjecture is true for two graphs then it is true for the join of these graphs. Related results for the graph complement conjecture (and the positive semidefinite version) for joins of graphs are also established. We also report on the use of recent results on partial k-trees to establish the graph complement conjecture for graphs of low minimum rank.

Comments

This is a manuscript of an article from Linear Algebra and its Applications 436 (2012): 4373, doi:10.1016/j.laa.2010.12.024. Posted with permission.

Rights

This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

Copyright Owner

Elsevier Inc.

Language

en

File Format

application/pdf

Published Version

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