Article ID Journal Published Year Pages File Type
4655454 Journal of Combinatorial Theory, Series A 2013 8 Pages PDF
Abstract

We give upper bounds for the number Φℓ(G) of matchings of size ℓ in (i) bipartite graphs G=(X∪Y,E) with specified degrees dx (x∈X), and (ii) general graphs G=(V,E) with all degrees specified. In particular, for d-regular, N-vertex graphs, our bound is best possible up to an error factor of the form exp[od(1)N], where od(1)→0 as d→∞. This represents the best progress to date on the “Upper Matching Conjecture” of Friedland, Krop, Lundow and Markström.Some further possibilities are also suggested.

Related Topics
Physical Sciences and Engineering Mathematics Discrete Mathematics and Combinatorics