English
Related papers

Related papers: A sufficient condition for a balanced bipartite di…

200 papers

For a bipartite graph G, let h(G) be the largest t such that either G or the bipartite complement of G contain K_{t,t}. For a class F of graphs, let h(F)= min {h(G): G\in F}. We say that a bipartite graph H is strongly acyclic if neither H…

Combinatorics · Mathematics 2019-03-26 Maria Axenovich , Casey Tompkins , Lea Weber

A digraph is eulerian if it is connected and every vertex has its in-degree equal to its out-degree. Having a spanning eulerian subdigraph is thus a weakening of having a hamiltonian cycle. In this paper, we first characterize the pairs…

Discrete Mathematics · Computer Science 2019-05-28 Jørgen Bang-Jensen , Frédéric Havet , Anders Yeeo

This paper addresses two open questions posed in [27] regarding the balanced domination number in graphs. We show that three new classes of graphs, those of convex polytopes A_n, D_n, and Rn'', are d-balanced. Further, we provide a…

Combinatorics · Mathematics 2025-11-12 Bojan Nikolic , Marko Djukanovic

We show that every 3-uniform hypergraph with $n$ vertices and minimum vertex degree at least $(5/9+o(1))\binom{n}2$ contains a tight Hamiltonian cycle. Known lower bound constructions show that this degree condition is asymptotically…

Combinatorics · Mathematics 2019-06-13 Christian Reiher , Vojtěch Rödl , Andrzej Ruciński , Mathias Schacht , Endre Szemerédi

Suppose $\Gamma$ is a finite simple graph. If $D$ is a dominating set of $\Gamma$ such that each $x\in D$ is contained in the set of vertices of an odd cycle of $\Gamma$, then we say that $D$ is an odd dominating set for $\Gamma$. For a…

Group Theory · Mathematics 2020-03-09 Mahdi Ebrahimi

A graph $G$ is $l$-path Hamiltonian if every path of length not exceeding $l$ is contained in a Hamiltonian cycle. It is well known that a 2-connected, $k$-regular graph $G$ on at most $3k-1$ vertices is edge-Hamiltonian if for every edge…

Combinatorics · Mathematics 2022-03-10 Xia Li , Weihua Yang

We study sufficient conditions for the existence of Hamilton cycles in uniformly dense $3$-uniform hypergraphs. Problems of this type were first considered by Lenz, Mubayi, and Mycroft for loose Hamilton cycles and Aigner-Horev and Levy…

Combinatorics · Mathematics 2020-05-27 Pedro Araújo , Simón Piga , Mathias Schacht

In this article we prove a necessary and a sufficient condition for a finite subset of the special linear group to be dominated. These conditions are purely geometric in nature, as they only involve the trace and the eigenvectors of the…

Dynamical Systems · Mathematics 2026-05-11 Argyrios Christodoulou

Let $\Gamma$ denote a bipartite graph with vertex set $X$, color partitions $Y$, $Y'$, and assume that every vertex in $Y$ has eccentricity $D\ge 3$. For $z\in X$ and a non-negative integer $i$, let $\Gamma_{i}(z)$ denote the set of…

Combinatorics · Mathematics 2022-01-17 Blas Fernandez , Safet Penjic

In this paper, we establish a tight sufficient condition for the Hamiltonicity of graphs with large minimum degree in terms of the signless Laplacian spectral radius and characterize all extremal graphs. Moreover, we prove a similar result…

Combinatorics · Mathematics 2017-10-25 Yawen Li , Yao liu , Xing Peng

A digraph $D=(V,A)$ of order $n\geq 3$ is pancyclic, whenever $D$ contains a directed cycle of length $k$ for each $k\in\{3,...,n\}$; and D is vertex-pancyclic iff, for each vertex $v\in V$ and each $k\in \{3,...,n\}$, $D$ contains a…

Combinatorics · Mathematics 2021-04-07 Narda Cordero-Michel , Hortensia Galeana-Sánchez

Recently, Milani\v{c} and Trotignon introduced the class of equistarable graphs as graphs without isolated vertices admitting positive weights on the edges such that a subset of edges is of total weight $1$ if and only if it forms a maximal…

Combinatorics · Mathematics 2015-02-24 Endre Boros , Nina Chiarelli , Martin Milanič

Barnette's Conjecture claims that all cubic, 3-connected, planar, bipartite graphs are Hamiltonian. We give a translation of this conjecture into the matching-theoretic setting. This allows us to relax the requirement of planarity to give…

Combinatorics · Mathematics 2022-08-17 Maximilian Gorsky , Raphael Steiner , Sebastian Wiederrecht

The bipartite independence number of a graph $G$, denoted as $\tilde\alpha(G)$, is the minimal number $k$ such that there exist positive integers $a$ and $b$ with $a+b=k+1$ with the property that for any two sets $A,B\subseteq V(G)$ with…

Combinatorics · Mathematics 2023-02-27 Nemanja Draganić , David Munhá Correia , Benny Sudakov

A \emph{mixed dihedral group} is a group $H$ with two disjoint subgroups $X$ and $Y$, each elementary abelian of order $2^n$, such that $H$ is generated by $X\cup Y$, and $H/H'\cong X\times Y$. In this paper we give a sufficient condition…

Combinatorics · Mathematics 2023-04-24 Daniel R. Hawtin , Cheryl E. Praeger , Jin-Xin Zhou

Let X be a reflexive Banach space and Y its dual. In this paper we find necessary and sufficient conditions for the existence of a bipotential for a blurred maximal cyclically monotone graph. Equivalently, we find a necessary and sufficient…

Functional Analysis · Mathematics 2019-02-18 Marius Buliga , Gery de Saxce , Claude Vallee

For a undirected simple graph $G$, let $d_i(G)$ be the number of $i$-element dominating vertex set of $G$. The domination polynomial of the graph $G$ is defined as $$D(G, x) = \sum_{i = 1}^n d_i(G)x^i.$$ Alikhani and Peng conjectured that…

Combinatorics · Mathematics 2021-11-03 Shengtong Zhang

In 2003, Fischermann et al. considered the maximum size of \textit{uniquely-dominatable} graphs, graphs whose dominating number is realized only by a unique dominating set. They conjectured a size bound and provide a general graph…

Combinatorics · Mathematics 2025-11-04 Garrison Koch , Darren Narayan

Given a digraph D, the minimum semi-degree of D is the minimum of its minimum indegree and its minimum outdegree. D is k-ordered Hamiltonian if for every ordered sequence of k distinct vertices there is a directed Hamilton cycle which…

Combinatorics · Mathematics 2007-07-12 Daniela Kühn , Deryk Osthus , Andrew Young

Let $n\geq 6,k\geq 0$ be two integers. Let $H$ be a graph of order $n$ with $k$ components, each of which is an even cycle of length at least $6$ and $G$ be a bipartite graph with bipartition $(X,Y)$ such that $|X|=|Y|\geq n/2$. In this…

Combinatorics · Mathematics 2019-04-04 Shengning Qiao , Bing Chen