English
Related papers

Related papers: Intrinsic Chirality of Multipartite Graphs

200 papers

In this paper, we discover all the triangle-free graphs that are competition graphs of multipartite tournaments.

Combinatorics · Mathematics 2023-03-23 Myungho Choi , Minki Kwak , Suh-Ryung Kim

In this paper, we give a characterization of the class of all circular-arc graphs whose schemes are association. Moreover, all association schemes which are the scheme of a circular-arc graph are characterized, specially it is proved that…

Combinatorics · Mathematics 2015-01-27 Fatemeh Raei Barandagh , Amir Rahnamai Barghi

An intense activity is nowadays devoted to the definition of models capturing the properties of complex networks. Among the most promising approaches, it has been proposed to model these graphs via their clique incidence bipartite graphs.…

Discrete Mathematics · Computer Science 2021-03-09 Matthieu Latapy , Thi Ha Duong Phan , Christophe Crespelle , Thanh Qui Nguyen

We characterize which automorphisms of an arbitrary complete bipartite graph $K_{n,m}$ can be induced by a homeomorphism of some embedding of the graph in $S^3$.

Geometric Topology · Mathematics 2018-08-14 Erica Flapan , Nicole Lehle , Blake Mellor , Matt Pittluck , Xan Vongsathorn

When $\mathcal{C}$ is a chordal clutter in the sense of Woodroofe or Emtander, we show that the complement clutter is edgewise strongly shellable. When $\mathcal{C}$ is indeed a finite simple graph, we study various characterizations of…

Combinatorics · Mathematics 2016-04-20 Jin Guo , Yi-Huang Shen , Tongsuo Wu

A strong clique in a graph is a clique intersecting every maximal independent set. We study the computational complexity of six algorithmic decision problems related to strong cliques in graphs and almost completely determine their…

Combinatorics · Mathematics 2018-08-28 Ademir Hujdurović , Martin Milanič , Bernard Ries

In the present paper, exterior algebraic shifting and symmetric algebraic shifting of bipartite graphs and chordal graphs are studied. First, we will determine the symmetric algebraic shifted graph of complete bipartite graphs. It turns out…

Combinatorics · Mathematics 2008-04-11 Satoshi Murai

A shelling of a graph, viewed as an abstract simplicial complex that is pure of dimension 1, is an ordering of its edges such that every edge is adjacent to some other edges appeared previously. In this paper, we focus on complete bipartite…

Combinatorics · Mathematics 2021-02-11 Yibo Gao , Junyao Peng

In this paper, we give a lengthy proof of a small result! A graph is bisplit if its vertex set can be partitioned into three stable sets with two of them inducing a complete bipartite graph. We prove that these graphs satisfy the…

Discrete Mathematics · Computer Science 2023-06-22 Laurent Beaudou , Giacomo Kahn , Matthieu Rosenfeld

In this paper, we give a necessary and sufficient condition for the integrality of Cayley graphs over the dihedral group $D_n=\langle a,b\mid a^n=b^2=1,bab=a^{-1}\rangle$. Moreover, we also obtain some simple sufficient conditions for the…

Combinatorics · Mathematics 2016-06-08 Lu Lu , Qiongxiang Huang , Xueyi Huang

Each finite and connected bipartite graph induces a finite collection of non-isomorphic dessins d'enfants, that is, $2$-cell embeddings of it into some closed orientable surface. We describe an algorithm to compute all these dessins…

Combinatorics · Mathematics 2017-08-24 Ruben A. Hidalgo

In this paper we deal with a subclass of chordal graphs, which are simultaneously strictly chordal and interval, the strictly interval graphs. We present a new characterization of the class that leads to a simple linear recognition…

Discrete Mathematics · Computer Science 2026-05-19 Claudia Justel , Lilian Markenzon

Here we prove that counting maximum matchings in planar, bipartite graphs is #P-complete. This is somewhat surprising in the light that the number of perfect matchings in planar graphs can be computed in polynomial time. We also prove that…

Computational Complexity · Computer Science 2021-03-09 Istvan Miklos , Miklos Kresz

Xuding Zhu introduced a refined scale of choosability in 2020 and observed that the four color theorem is tight on this scale. We formalize and explore this idea of tightness in what we call strictly colorable graphs. We then characterize…

Combinatorics · Mathematics 2023-07-12 Evan Leonard

The aim of this paper is to show that any finite undirected bipartite graph can be considered as a polynomial $p \in \mathbb{N}[x]$, and any directed finite bipartite graph can be considered as a polynomial $p\in\mathbb{N}[x,y]$, and vise…

Rings and Algebras · Mathematics 2019-03-26 Andrey Grinblat , Viktor Lopatkin

Let $G$ be a group. The intersection graph of subgroups of $G$, denoted by $\mathscr{I}(G)$, is a graph with all the proper subgroups of $G$ as its vertices and two distinct vertices in $\mathscr{I}(G)$ are adjacent if and only if the…

Group Theory · Mathematics 2015-06-03 R. Rajkumar , P. Devi

A totally silver coloring of a graph G is a k--coloring of G such that for every vertex v \in V(G), each color appears exactly once on N[v], the closed neighborhood of v. A totally silver graph is a graph which admits a totally silver…

Combinatorics · Mathematics 2013-02-14 M. Ghebleh , E. S. Mahmoodian

Strictly Chordality-k graphs (SC_k graphs) are graphs which are either cycle free or every induced cycle is exactly k, for some fixed k, k \geq 3. Note that k = 3 and k = 4 are precisely the Chordal graphs and Chordal Bipartite graphs,…

Discrete Mathematics · Computer Science 2017-09-04 S. Dhanalakshmi , N. Sadagopan

This paper is a survey on Extremal Graph Theory, primarily focusing on the case when one of the excluded graphs is bipartite. On one hand we give an introduction to this field and also describe many important results, methods, problems, and…

Combinatorics · Mathematics 2013-07-02 Zoltán Füredi , Miklós Simonovits

We introduce and study embeddings of graphs in finite projective planes, and present related results for some families of graphs including complete graphs and complete bipartite graphs. We also make connections between embeddings of graphs…

Combinatorics · Mathematics 2013-10-02 Keith Mellinger , Ryan Vaughn , Oscar Vega