Results 61 to 70 of about 6,654 (223)

On the Hardness of Switching to a Small Number of Edges

Journal of Graph Theory, EarlyView.
ABSTRACT Seidel's switching is a graph operation which makes a given vertex adjacent to precisely those vertices to which it was non‐adjacent before, while keeping the rest of the graph unchanged. Two graphs are called switching‐equivalent if one can be made isomorphic to the other one by a sequence of switches. Jelínková et al. [DMTCS 13, no. 2, 2011]
Vít Jelínek, Eva Jelínková, Jan Kratochvíl   +2 more
wiley   +1 more source

ISOMORFISMA DIGRAPH EKSENTRIS DENGAN DIGRAPH ASALNYA [PDF]

, 2005
Digraph sikel Cn adalah digraph yang paling sederhana yang digraph eksentrisnya isomorfis dengan digraph asalnya. Sedangkan digraph lengkap Kn adalah digraph komplit yang digraph eksentrisnya isomorfis bahkan sama dengan digraph asalnya, sehingga untuk ...
IDA RIYAWATI, 0800112306
core  

The homology digraph of a preordered space [PDF]

, 2023
This paper studies a notion of directed homology for preordered spaces, called the homology digraph. We show that the homology digraph is a directed homotopy invariant and establish variants of the main results of ordinary singular homology theory for ...
Kahl, Thomas, Faustino, Catarina
core   +1 more source

Majority Digraphs

Proceedings of the American Mathematical Society, 2016
A majority digraph is a finite simple digraph G = ( V ,
Lai, Tri, Endrullis, Jörg, Moss, Lawrence S.   +2 more
openaire   +4 more sources

A Min–Max Relation on Dicuts and Dijoins in Weighted Chordal Digraphs

Journal of Graph Theory, EarlyView.
ABSTRACT In a digraph, a dicut is a cut where all the arcs cross in one direction. A dijoin is a subset of arcs that intersects every dicut. Edmonds and Giles conjectured that in a weighted digraph, the minimum weight of a dicut is equal to the maximum size of a packing of dijoins. This has been disproved. However, the unweighted version conjectured by
Gérard Cornuéjols, Siyue Liu, R. Ravi
wiley   +1 more source

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, Alewyn Petrus Burger, Marietjie Frick   +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, Grace Estrada, Carmelita Loquias, Reuella J Bacalso, Lanndon Ocampo   +4 more
doaj   +1 more source

Adamant digraphs

Discrete Mathematics, 1988
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
MARCHIORO P., MORGANA A., PETRESCHI, Rossella, SIMEONE B.   +3 more
openaire   +3 more sources

An End Degree for Digraphs

Journal of Graph Theory, EarlyView.
ABSTRACT In this paper we define a degree for ends of infinite digraphs. The well‐definedness of our definition in particular resolves a problem by Zuther. Furthermore, we extend our notion of end degree to also respect, among others, the vertices dominating the end, which we denote as combined end degree.
Matthias Hamann, Karl Heuer
wiley   +1 more source

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, Sepehr Hajebi, Nicolas Trotignon   +2 more
wiley   +1 more source