Clique Minors In Double-Critical Graphs
Keywords
clique minor; double-critical graph; separating set
Abstract
A connected t-chromatic graph G is double-critical if G - { u,v } is (t-2) -colorable for each edge ∈ E(G). A long-standing conjecture of Erdős and Lovász that the complete graphs are the only double-critical t-chromatic graphs remains open for all t ≥ 6. Given the difficulty in settling Erdős and Lovász's conjecture and motivated by the well-known Hadwiger's conjecture, Kawarabayashi, Pedersen, and Toft proposed a weaker conjecture that every double-critical t-chromatic graph contains a Kt minor and verified their conjecture for t ≤ 7. Albar and Gonçalves recently proved that every double-critical 8-chromatic graph contains a K8 minor, and their proof is computer assisted. In this article, we prove that every double-critical t-chromatic graph contains a Kt minor for all t ≤ 9 Our proof for t ≤ 8 is shorter and computer free.
Publication Date
6-1-2018
Publication Title
Journal of Graph Theory
Volume
88
Issue
2
Number of Pages
347-355
Document Type
Article
Personal Identifier
scopus
DOI Link
https://doi.org/10.1002/jgt.22216
Copyright Status
Unknown
Socpus ID
85034272196 (Scopus)
Source API URL
https://api.elsevier.com/content/abstract/scopus_id/85034272196
STARS Citation
Rolek, Martin and Song, Zi Xia, "Clique Minors In Double-Critical Graphs" (2018). Scopus Export 2015-2019. 9630.
https://stars.library.ucf.edu/scopus2015/9630