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Excluding Induced Subdivisions of the Bull and Related Graphs

✍ Scribed by Maria Chudnovsky; Irena Penev; Alex Scott; Nicolas Trotignon


Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
233 KB
Volume
71
Category
Article
ISSN
0364-9024

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✦ Synopsis


Abstract

For any graph H, let Forb*(H) be the class of graphs with no induced subdivision of H. It was conjectured in [J Graph Theory, 24 (1997), 297–311] that, for every graph H, there is a function f~H~: ℕ→ℝ such that for every graph G∈Forb*(H), Ο‡(G)≀f~H~(Ο‰(G)). We prove this conjecture for several graphs H, namely the paw (a triangle with a pendant edge), the bull (a triangle with two vertex‐disjoint pendant edges), and what we call a β€œnecklace,” that is, a graph obtained from a path by choosing a matching such that no edge of the matching is incident with an endpoint of the path, and for each edge of the matching, adding a vertex adjacent to the ends of this edge. Β© 2011 Wiley Periodicals, Inc. J Graph Theory 71:49–68, 2012


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