Title
Polynomial bounds for chromatic number II: Excluding a star-forest
Abstract
The Gyarfas-Sumner conjecture says that for every forest H, there is a function f(H) such that if G is H-free then chi(G) <= f(H) (omega(G)) (where chi, omega are the chromatic number and the clique number of G). Louis Esperet conjectured that, whenever such a statement holds, f(H) can be chosen to be a polynomial. The Gyarfas-Sumner conjecture is only known to be true for a modest set of forests H, and Esperet's conjecture is known to be true for almost no forests. For instance, it is not known when H is a five-vertex path. Here we prove Esperet's conjecture when each component of H is a star.
Year
DOI
Venue
2022
10.1002/jgt.22829
JOURNAL OF GRAPH THEORY
Keywords
DocType
Volume
chromatic number, colouring, Gyarfas-Sumner conjecture, induced subgraph, chi-boundedness
Journal
101
Issue
ISSN
Citations 
2
0364-9024
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Alex Scott100.68
Paul D. Seymour22786314.49
Sophie Spirkl300.68