نتایج جستجو برای: perfect r matching

تعداد نتایج: 585013  

Journal: :Electr. J. Comb. 2010
Makoto Tagami

Beck et. al. characterized the grid graphs whose perfect matching polytopes are Gorenstein and they also showed that for some parameters, perfect matching polytopes of torus graphs are Gorenstein. In this paper, we complement their result, that is, we characterize the torus graphs whose perfect matching polytopes are Gorenstein. Beck et. al. also gave a method to construct an infinite family of...

Journal: :Combinatorica 2006
Shinya Fujita Ken-ichi Kawarabayashi Claudio L. Lucchesi Katsuhiro Ota Michael D. Plummer Akira Saito

In this paper, we study the relationship between forbidden subgraphs and the existence of a matching. Let H be a set of connected graphs, each of which has three or more vertices. A graph G is said to beH-free if no graph inH is an induced subgraph of G. We completely characterize the setH such that every connected H-free graph of sufficiently large even order has a perfect matching in the foll...

Journal: :International Journal of Geometric Methods in Modern Physics 2019

Journal: :Publicacions Matemàtiques 1989

Journal: :Discrete Mathematics 1991
Ralph J. Faudree Ronald J. Gould Linda M. Lesniak

Faudree, R.J., R.J. Gould and L.M. Lesniak, Neighborhood conditions and edge-disjoint perfect matchings, Discrete Mathematics 91 (1991) 33-43. A graph G satisfies the neighborhood condition ANC(G) 2 m if, for all pairs of vertices of G, the union of their neighborhoods has at least m vertices. For a fixed positive integer k, let G be a graph of even order n which satisfies the following conditi...

2014
J. Lengler R. Nenadov N. Škorić

V := {ri}i=1 ∪ {ci}i=1 and E := {{ri, cj} | mi,j ≥ 1/n}. The main observation is that if G contains a perfect matching then there exists a desired permutation. To see that, let us assume that P = {e1, . . . , en} is a subset of the edges of G which form a perfect matching, with ei = {ri, cji}. Then setting π(i) := ji satisfies the desired properties: since P is a matching we have that π is a bi...

Journal: :Discrete Mathematics 2008
Xiumei Wang Zhenkun Zhang Yixun Lin

Matching extendability is significant in graph theory and its applications. The basic notion in this direction is n-extendability introduced by Plummer in 1980. Motivated by the different natures of bipartite matchings and non-bipartite matchings, this paper investigates bipartite-matching extendable (BM-extendable) graphs. A graph G is said to be BM-extendable if every matching M which is a pe...

Journal: :iranian journal of mathematical chemistry 2016
h. bian b. liu h. yu

the idea of “forcing” has long been used in many research fields, such as colorings, orientations, geodetics and dominating sets in graph theory, as well as latin squares, block designs and steiner systems in combinatorics (see [1] and the references therein). recently, the forcing on perfect matchings has been attracting more researchers attention. a forcing set of m is a subset of m contained...

2009
Xuelian Wen Zihui Yang Zan-Bo Zhang Mariko Hagita

A near perfect matching is a matching covering all but one vertex in a graph. Let G be a connected graph and n ≤ (|V (G)|−2)/2 be a positive integer. If any n independent edges in G are contained in a near perfect matching, then G is said to be defect n-extendable. This paper presents two construction characterizations of defect n-extendable bipartite graphs and a necessary condition for minima...

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