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5 votes
0 answers
249 views

Counting perfect matchings with integrals

Has anyone used the Joni-Rota-Godsil integral formula (see details below) to count perfect matchings of square-grid graphs, Aztec diamond graphs, hexagon-honeycomb graphs, etc.? (Or even just to ...
James Propp's user avatar
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1 vote
1 answer
190 views

Converse of Petersen's 2-Factorization Theorem

Definition: A $k$-factor of a graph is a spanning $k$-regular subgraph. Definition: A $k$-factorization of a graph is a partition of the edge set into $k$-factors. Petersen's celebrated ...
Felix Goldberg's user avatar
0 votes
1 answer
773 views

Counting matchings in a bipartite matching-covered graph

A graph is called matching-covered if every edge is containd in a perfect matching. (Such graphs are also sometimes called "elementary", e.g. in Chapter 4 of "Matching Theory" by Lovasz & Plummer)....
Felix Goldberg's user avatar
3 votes
1 answer
131 views

A graph $G$ with two $K_6$ subgraphs, in which any one-factor of $G$ induces a one-factor in exactly one of the $K_6$ subgraphs?

I'm seeking a simple graph $G$ of the following type: It contains two disjoint copies of $K_6$ (the complete graph on 6 nodes), $H$ and $H'$ say. Any one-factor of $G$ must contain either (a) a one ...
Douglas S. Stones's user avatar
6 votes
1 answer
230 views

A non-distinct system of representative edges

I have the following problem: Let $ \mathcal{G} = (G_{i})\_{i} $ be a collection of graphs on the same vertex set. I would like to find a "system of representative edges" $ f : \mathcal{G} \...
julkiewicz's user avatar
8 votes
1 answer
2k views

Condition on a bipartite graph to have an $m$-factor

This might be the most stupid question I am ever posting here: I am asking for a proof or a counterexample to a problem I proposed on MathLinks long ago. Let $G$ be a bipartite graph, i. e., a graph ...
darij grinberg's user avatar

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