Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4653431 | European Journal of Combinatorics | 2015 | 20 Pages |
Abstract
We consider an extremal problem motivated by a question of ErdÅs and Rothschild (ErdÅs, 1974) regarding edge-colorings of graphs avoiding a given monochromatic subgraph. An extension of this problem to edge-colorings avoiding fixed subgraphs with a prescribed coloring has been studied by Balogh (Balogh, 2006). In this work, we consider the following natural generalization of the original ErdÅs-Rothschild question: given a natural number r and a graph F, an r-pattern P of F is a partition of the edge set of F into r (possibly empty) classes, and an r-coloring of the edge set of a graph G is said to be (F,P)-free if it does not contain a copy of F in which the partition of the edge set induced by the coloring has a copy of P. Let cr,(F,P)(G) be the number of (F,P)-free r-colorings of a graph G. For large n, we maximize this number over all n-vertex graphs for a large class of patterns in matchings and we describe the graphs that achieve this maximum.
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
Carlos Hoppen, Hanno Lefmann,