Results 61 to 70 of about 8,697 (224)
DIGRAPH GROUPS AND RELATED GROUPS [PDF]
, 2022 This thesis investigates finite digraph groups and related groups like the generalization of Johnson and Mennicke groups. Cuno and Williams introduced the term "digraph group" for the first time in [9], 2020.
Cihan, Mehmet Sefa
core +3 more sources
The Existence of Planar Hypotraceable Oriented Graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2017 A digraph is \emph{traceable} if it has a path that visits every vertex. A digraph $D$ is \emph{hypotraceable} if $D$ is not traceable but $D-v$ is traceable for every vertex $v\in V(D)$.
Susan van Aardt +2 more
doaj +1 more source
Domination in Fuzzy Directed Graphs
Mathematics, 2021 A new domination parameter in a fuzzy digraph is proposed to espouse a contribution in the domain of domination in a fuzzy graph and a directed graph. Let GD*=V,A be a directed simple graph, where V is a finite nonempty set and A=x,y:x,y∈V,x≠y.
Enrico Enriquez +4 more
doaj +1 more source
Digraph homomorphisms on \(Z_n\)-digraph
Malaya Journal of Matematik, 2020 A graph homomorphism is a mapping between two graphs that respect their structure. In this paper we develop some results related to digraph homomorphisms for the class of \({\overrightarrow{Z_n}}^{-}\)-digraphs. We will begin by giving some standard definitions, then expanding our focus to specifically study different types of digraph homomorphisms. In
null Jimly Manuel, null Bindhu K Thomas
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Tree Independence Number III. Thetas, Prisms and Stars
Journal of Graph Theory, EarlyView.ABSTRACT We prove that for every t ∈ N $t\in {\mathbb{N}}$ there exists τ = τ ( t ) ∈ N $\tau =\tau (t)\in {\mathbb{N}}$ such that every (theta, prism, K 1 , t ${K}_{1,t}$)‐free graph has tree independence number at most τ $\tau $ (where we allow “prisms” to have one path of length zero).
Maria Chudnovsky +2 more
wiley +1 more source
4-Transitive Digraphs I: The Structure of Strong 4-Transitive Digraphs
Discussiones Mathematicae Graph Theory, 2013 Let D be a digraph, V (D) and A(D) will denote the sets of vertices and arcs of D, respectively. A digraph D is transitive if for every three distinct vertices u, v,w ∈ V (D), (u, v), (v,w) ∈ A(D) implies that (u,w) ∈ A(D).
Hernández-Cruz César
doaj +1 more source
Skew-signings of positive weighted digraphs
Arab Journal of Mathematical Sciences, 2018 An arc-weighted digraph is a pair (D , ω) where D is a digraph and ω is an arc-weight function that assigns to each arc u v of D a nonzero real number ω (u v) .
Kawtar Attas +2 more
doaj +1 more source
Two‐Block Paths in Oriented Graphs of Large Semidegree
Journal of Graph Theory, EarlyView.ABSTRACT We study the existence of oriented paths with two blocks in oriented graphs under semidegree conditions. A block of an oriented path is a maximal directed subpath. Given positive integers k $k$ and ℓ $\ell $ with k / 2 ≤ ℓ < k $k/2\le \ell \lt k$, we establish a semidegree function that guarantees the containment of every oriented path with ...
Irena Penev +4 more
wiley +1 more source
Discrete Mathematics, 1997 ``This paper focuses on a family of vertex symmetric digraphs \dots which were introduced by \textit{M. L. Fiol} [The relation between digraphs and groups through Cayley digraphs, Universitat Autònoma de Barcelona, 1984 (in Catalan)].'' For integers \(k\) and \(n\), \(1\leq k\leq n-1\), a digraph \(P(n,k)\) has as vertices the \(k\)-permutations of ...
Josep M. Brunat +2 more
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Journal of Graph Theory, EarlyView.ABSTRACT A 2‐edge‐coloured graph G $G$ is called locally complete if for each vertex v $v$, the vertices adjacent to v $v$ through edges of the same colour induce a complete subgraph in G $G$. Locally complete 2‐edge‐coloured graphs have nice properties, and there exists a polynomial algorithm to decide whether such a graph has an alternating ...
Jørgen Bang‐Jensen, Jing Huang
wiley +1 more source