38 research outputs found

    Gallai-Edmonds Structure Theorem for Weighted Matching Polynomial

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    In this paper, we prove the Gallai-Edmonds structure theorem for the most general matching polynomial. Our result implies the Parter-Wiener theorem and its recent generalization about the existence of principal submatrices of a Hermitian matrix whose graph is a tree. keywords:Comment: 34 pages, 5 figure

    Extensions of Barrier Sets to Nonzero Roots of the Matching Polynomials

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    In matching theory, barrier sets (also known as Tutte sets) have been studied extensively due to its connection to maximum matchings in a graph. In this paper, we first define θ\theta-barrier sets. Our definition of a θ\theta-barrier set is slightly different from that of a barrier set. However we show that θ\theta-barrier sets and barrier sets have similar properties. In particular, we prove a generalized Berge's Formula and give a characterization for the set of all θ\theta-special vertices in a graph

    Graphs with few matching roots

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    We determine all graphs whose matching polynomials have at most five distinct zeros. As a consequence, we find new families of graphs which are determined by their matching polynomial.Comment: 14 pages, 7 figures, 1 appendix table. Final version. Some typos are fixe

    Matching measure, Benjamini-Schramm convergence and the monomer-dimer free energy

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    We define the matching measure of a lattice L as the spectral measure of the tree of self-avoiding walks in L. We connect this invariant to the monomer-dimer partition function of a sequence of finite graphs converging to L. This allows us to express the monomer-dimer free energy of L in terms of the measure. Exploiting an analytic advantage of the matching measure over the Mayer series then leads to new, rigorous bounds on the monomer-dimer free energies of various Euclidean lattices. While our estimates use only the computational data given in previous papers, they improve the known bounds significantly.Comment: 18 pages, 3 figure

    Min-max results in combinatorial optimization

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