English
Related papers

Related papers: The 2-Factor Polynomial Detects Even Perfect Match…

200 papers

We prove that in every bipartite Cayley graph of every non-amenable group, there is a perfect matching that is obtained as a factor of independent uniform random variables. We also discuss expansion properties of factors and improve the…

Probability · Mathematics 2011-09-20 Russell Lyons , Fedor Nazarov

A 2-edge-coloured graph $G$ is {\bf supereulerian} if $G$ contains a spanning closed trail in which the edges alternate in colours. An {\bf eulerian factor} of a 2-edge-coloured graph is a collection of vertex disjoint induced subgraphs…

Combinatorics · Mathematics 2020-04-07 Jørgen Bang-Jensen , Thomas Bellitto , Anders Yeo

A graph has a perfect partition if all its perfect matchings can be partitioned so that each part is a 1-factorization of the graph. Let $L_{rm, r}=K_{rm,rm}-mK_{r,r}$. We first give a formula to count the number of perfect matchings of…

Combinatorics · Mathematics 2012-12-27 Chi-Kwong Li , Jeff Soosiah , Gexin Yu

In this paper, we introduce a corresponding between bipartite graphs with a perfect matching and digraphs, which implicates an equivalent relation between the extendibility of bipartite graphs and the strongly connectivity of digraphs. Such…

Combinatorics · Mathematics 2010-11-22 Zan-Bo Zhang , Dingjun Lou

Aslam presents an algorithm he claims will count the number of perfect matchings in any incomplete bipartite graph with an algorithm in the function-computing version of NC, which is itself a subset of FP. Counting perfect matchings is…

Computational Complexity · Computer Science 2009-05-15 Frank Ferraro , Garrett Hall , Andrew Wood

The biplanar crossing number of a graph $G$ is the minimum number of crossings over all possible drawings of the edges of $G$ in two disjoint planes. We present new bounds on the biplanar crossing number of complete graphs and complete…

Computational Geometry · Computer Science 2021-07-08 Alireza Shavali , Hamid Zarrabi-Zadeh

We characterize hyperfinite bipartite graphings that admit measurable perfect matchings. In particular, we prove that every regular hyperfinite bipartite graphing admits a measurable perfect matching if it is one-ended or the degree is odd.…

Combinatorics · Mathematics 2022-07-01 Matthew Bowen , Gabor Kun , Marcin Sabok

We develop a space-level refinement of the $2$-factor homology by constructing a stable homotopy type associated to a certain family $\mathscr{G}$ of planar trivalent graphs equipped with perfect matchings. Specifically, we define a cover…

Geometric Topology · Mathematics 2025-08-19 Nilangshu Bhattacharyya

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 prove that any quasirandom dense large graph in which all degrees are equal and even can be decomposed into any given collection of two-factors (2-regular spanning subgraphs). A special case of this result gives a new solution to the…

Combinatorics · Mathematics 2020-04-22 Peter Keevash , Katherine Staden

We systematically investigate the complexity of counting subgraph patterns modulo fixed integers. For example, it is known that the parity of the number of $k$-matchings can be determined in polynomial time by a simple reduction to the…

Computational Complexity · Computer Science 2021-07-02 Radu Curticapean , Holger Dell , Thore Husfeldt

Let $\mathrm{pm}(G)$ denote the number of perfect matchings of a graph $G$, and let $K_{r\times 2n/r}$ denote the complete $r$-partite graph where each part has size $2n/r$. Johnson, Kayll, and Palmer conjectured that for any perfect…

Combinatorics · Mathematics 2022-11-04 Sam Spiro , Erlang Surya

We investigate generalisations of 1-factorisations and hyperfactorisations of the complete graph $K_{2n}$. We show that they are special subsets of the association scheme obtained from the Gelfand pair $(S_{2n},S_2 \wr S_n)$. This unifies…

Combinatorics · Mathematics 2026-03-19 John Bamberg , Lukas Klawuhn

The aim of this paper is to show that there exists a deterministic algorithm that can be applied to compute the factors of a polynomial of degree 2, defined over a finite field, given certain conditions.

Number Theory · Mathematics 2017-09-19 Amalaswintha Wolfsdorf

The matching polynomial of a graph is the generating function of the numbers of its matchings with respect to their cardinality. A graph polynomial is polynomial reconstructible, if its value for a graph can be determined from its values…

Combinatorics · Mathematics 2014-04-15 Xueliang Li , Yongtang Shi , Martin Trinks

A graph is called matching covered if for its every edge there is a maximum matching containing it. It is shown that minimal matching covered graphs contain a perfect matching.

Discrete Mathematics · Computer Science 2007-07-16 V. V. Mkrtchyan

We prove that every 3-connected 2-indivisible infinite planar graph has a 1-way infinite 2-walk. (A graph is 2-indivisible if deleting finitely many vertices leaves at most one infinite component, and a 2-walk is a spanning walk using every…

Combinatorics · Mathematics 2015-08-28 Daniel P. Biebighauser , M. N. Ellingham

The toughness of a graph $G$ is defined as the minimum value of $|S|/c(G-S)$ over all cutsets $S$ of $G$ if $G$ is noncomplete, and is defined to be $\infty$ if $G$ is complete. For a real number $t$, we say that $G$ is $t$-tough if its…

Combinatorics · Mathematics 2025-07-02 Lili Hao , Hui Ma , Songling Shan , Weihua Yang

We present an algorithm for determining whether a bipartite graph $G$ is 2-chordal (formerly doubly chordal bipartite). At its core this algorithm is an extension of the existing efficient algorithm for determining whether a graph is…

Combinatorics · Mathematics 2021-04-13 Austin Alderete

For a graph $G$ let $L(G)$ and $l(G)$ denote the size of the largest and smallest maximum matching of a graph obtained from $G$ by removing a maximum matching of $G$. We show that $L(G)\leq 2l(G),$ and $L(G)\leq (3/2)l(G)$ provided that $G$…

Discrete Mathematics · Computer Science 2011-11-17 Artur Khojabaghyan , Vahan V. Mkrtchyan