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Related papers: Atoms of the matching measure

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Godsil observed the simple fact that the multiplicity of 0 as a root of the matching polynomial of a graph coincides with the classical notion of deficiency. From this fact he asked to what extent classical results in matching theory…

Combinatorics · Mathematics 2008-07-01 Cheng Yeaw Ku , William Chen

We introduce the matching measure of a finite graph as the uniform distribution on the roots of the matching polynomial of the graph. We analyze the asymptotic behavior of the matching measure for graph sequences with bounded degree. A…

Combinatorics · Mathematics 2021-08-31 Miklos Abért , Péter Csikvári , Péter Frenkel , Gábor Kun

For a graph $G$ with $n$ vertices, let $\nu(G)$ and $A(G)$ denote the matching number and adjacency matrix of $G$, respectively. The permanental polynomial of $G$ is defined as $\pi(G,x)={\rm per}(Ix-A(G))$. The permanental nullity of $G$,…

Combinatorics · Mathematics 2016-03-11 Tingzeng Wu , Hong-Jian Lai

In this note we present an infinite family of 2-connected graphs such that their matching polynomials have only integer zeros. This answers in negative a question of Akbari et al. [Graphs with integer matching polynomial zeros, Discrete…

Combinatorics · Mathematics 2021-09-14 Ebrahim Ghorbani

We construct, for every $d \geq 3$, a $d$-regular acyclic measurably bipartite graphing that admits no measurable perfect matching, resolving a problem of Kechris and Marks. A dense variant of our construction yields a coupling of two…

Combinatorics · Mathematics 2024-10-11 Gábor Kun

In this paper, we study graphs whose matching polynomial have only integer zeros. A graph is matching integral if the zeros of its matching polynomial are all integers. We characterize all matching integral traceable graphs.. We show that…

Combinatorics · Mathematics 2017-02-07 S. Akbari , P. Csikvari , A. Ghafari , S. Khalashi Ghezelahmad , M. Nahvi

In this paper, we study commutative zero-divisor semigroups determined by graphs. We prove a uniqueness theorem for a class of graphs. We show two classes of graphs that have no corresponding semigroups. In particular, any complete graph…

Rings and Algebras · Mathematics 2007-05-23 Tongsuo Wu , Li Chen

A new shortest proof of Kotzig's Theorem about graphs with unique perfect matching is presented in this paper. It is well known that Kotzig's theorem is a consequence of Yeo's Theorem about edge-colored graph without alternating cycle. We…

Combinatorics · Mathematics 2014-02-06 Gleb Nenashev

Counting maximum matchings in a graph is of great interest in statistical mechanics, solid-state chemistry, theoretical computer science, mathematics, among other disciplines. However, it is a challengeable problem to explicitly determine…

Combinatorics · Mathematics 2023-06-26 Tingzeng Wu , Xiaolin Zeng , Huazhong Lv

In this paper, we derive a set of equivalent conditions for the zero-divisor graph $\Gamma(Q)$ of a poset $Q$ with $0$ to be complemented, characterizing it in terms of quasi-complemented posets. Furthermore, we prove that the notions of a…

Combinatorics · Mathematics 2026-04-20 Anagha Khiste , Ganesh Tarte , Vinayak Joshi

In this paper we review the asymptotic matching conjectures for $r$-regular bipartite graphs, and their connections in estimating the monomer-dimer entropies in $d$-dimensional integer lattice and Bethe lattices. We prove new rigorous upper…

Combinatorics · Mathematics 2008-04-11 Shmuel Friedland , Elliot Krop , Per Hakan Lundow , Klas Markström

Given an undirected graph, are there $k$ matchings whose union covers all of its nodes, that is, a matching-$k$-cover? A first, easy polynomial solution from matroid union is possible, as already observed by Wang, Song and Yuan…

Combinatorics · Mathematics 2021-02-05 Dehia Ait Ferhat , Zoltán Király , András Sebő , Gautier Stauffer

We study the complexity of proving that a sparse random regular graph on an odd number of vertices does not have a perfect matching, and related problems involving each vertex being matched some pre-specified number of times. We show that…

Computational Complexity · Computer Science 2023-06-22 Per Austrin , Kilian Risse

We discuss the question whether the existence of perfect matchings in a cubic graph can be seen from the spectrum of its adjacency matrix. For regular graphs in general and for three edge-disjoint perfect matchings in a cubic graph (that…

Combinatorics · Mathematics 2026-01-08 Willem H. Haemers

We study hypergraphs which represent finite quantum event structures. We contribute to results of graph theory, regarding bounds on the number of edges, given the number of vertices. We develop a missing one for 3-graphs of girth 4. As an…

Quantum Algebra · Mathematics 2024-02-06 Vaclav Voracek

A vertex $v$ of a 2-connected cubic graph $G$ is $\lambda$-matchable if $G$ has a spanning subgraph in which $v$ has degree three whereas every other vertex has degree one, and we let $\lambda(G)$ denote the number of such vertices.…

Combinatorics · Mathematics 2025-10-15 Santhosh Raghul , Nishad Kothari

We introduce a graded homology theory for graded \'etale groupoids. For $\mathbb Z$-graded groupoids, we establish an exact sequence relating the graded zeroth-homology to non-graded one. Specialising to the arbitrary graph groupoids, we…

K-Theory and Homology · Mathematics 2019-01-23 Roozbeh Hazrat , Huanhuan Li

We prove that any non-amenable Cayley graph admits a factor of IID perfect matching. We also show that any connected d-regular vertex tran- sitive graph admits a perfect matching. The two results together imply that every Cayley graph…

Combinatorics · Mathematics 2012-11-13 Endre Csoka , Gabor Lippner

If $G$ is a bridgeless cubic graph, Fulkerson conjectured that we can find 6 perfect matchings $M_1,...,M_6$ of $G$ with the property that every edge of $G$ is contained in exactly two of them and Berge conjectured that its edge set can be…

Discrete Mathematics · Computer Science 2009-04-09 Jean-Luc Fouquet , Jean-Marie Vanherpe

Let $G$ be a connected graph with vertex set $V(G)=\{v_1,v_2,...,v_{\nu}\}$, which may have multiple edges but have no loops, and $2\leq d_G(v_i)\leq 3$ for $i=1,2,...,\nu$, where $d_G(v)$ denotes the degree of vertex $v$ of $G$. We show…

Combinatorics · Mathematics 2009-06-23 Weigen Yan , Fuji Zhang
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