Graph operations and upper bounds on graph homomorphism counts
Graph operations and upper bounds on graph homomorphism counts
Abstract We construct a family of countexamples to a conjecture of Galvin [5], which stated that for any n ‐vertex, d ‐regular graph G and any graph H (possibly with loops), urn:x-wiley:03649024:media:jgt22148:jgt22148-math-0001 where is the number of homomorphisms from G to H . By exploiting properties of the graph tensor …