Results 61 to 70 of about 835 (85)

What Moser Could Have Asked: Counting Hamilton Cycles in Tournaments [PDF]

, 2015
Moser asked for a construction of explicit tournaments on $n$ vertices having at least $(\frac{n}{3e})^n$ Hamilton cycles.
Calkin, Neil J., Novick, Beth, Ushijima-Mwesigwa, Hayato   +2 more
core   +2 more sources

Bounds on the Signed Roman k-Domination Number of a Digraph

Discussiones Mathematicae Graph Theory, 2019
Let k be a positive integer. A signed Roman k-dominating function (SRkDF) on a digraph D is a function f : V (D) → {−1, 1, 2} satisfying the conditions that (i) Σx∈N−[v]f(x) ≥ k for each v ∈ V (D), where N−[v] is the closed in-neighborhood of v, and (ii)
Chen Xiaodan, Hao Guoliang, Volkmann Lutz   +2 more
doaj   +1 more source

Some Results on 4-Transitive Digraphs

Discussiones Mathematicae Graph Theory, 2017
Let D be a digraph with set of vertices V and set of arcs A. We say that D is k-transitive if for every pair of vertices u, v ∈ V, the existence of a uv-path of length k in D implies that (u, v) ∈ A.
García-Vázquez Patricio Ricardo, Hernández-Cruz César   +1 more
doaj   +1 more source

Super Edge-Connectivity and Zeroth-Order Randić Index

Discussiones Mathematicae Graph Theory, 2020
Define the zeroth-order Randić index as R0(G)=∑x∈V(G)1dG(x),{R^0}\left( G \right) = \sum\nolimits_{x \in V\left( G \right)} {{1 \over {\sqrt {{d_G}} \left( x \right)}},} where dG(x) denotes the degree of the vertex x.
He Zhihong, Lu Mei
doaj   +1 more source

𝕮-inverse of graphs and mixed graphs

Open Mathematics
This article introduces a generalization of the concept of inverse graphs applicable to both graphs and mixed graphs. Given a graph GG with adjacency matrix A(G)A\left(G), the inverse graph G−1{G}^{-1} is defined such that its adjacency matrix is similar
Alomari Omar, Abudayah Mohammad, Ghanem Manal   +2 more
doaj   +1 more source

γ-Inverse graph of some mixed graphs

Special Matrices
Let GG be a graph. Then, the inverse graph G−1{G}^{-1} of GG is defined to be a graph that has adjacency matrix similar to the inverse of the adjacency matrix of GG, where the similarity matrix is ±1\pm 1 diagonal matrix. In this article, we introduced a
Boulahmar Wafa, Ghanem Manal, Abudayah Mohammad   +2 more
doaj   +1 more source

Causal structure learning in directed, possibly cyclic, graphical models

Journal of Causal Inference
We consider the problem of learning a directed graph G⋆{G}^{\star } from observational data. We assume that the distribution that gives rise to the samples is Markov and faithful to the graph G⋆{G}^{\star } and that there are no unobserved variables.
Semnani Pardis, Robeva Elina
doaj   +1 more source

γ-Cycles In Arc-Colored Digraphs

Discussiones Mathematicae Graph Theory, 2016
We call a digraph D an m-colored digraph if the arcs of D are colored with m colors. A directed path (or a directed cycle) is called monochromatic if all of its arcs are colored alike.
Galeana-Sánchez Hortensia, Gaytán-Gómez Guadalupe, Rojas-Monroy Rocío   +2 more
doaj   +1 more source

Complete graphs: the space of simplicial cones, and their path tree representation

, 2017
Let $G$ be a complete graph with $n+1$ vertices. In a recent paper of the authors, it is shown that the path trees of the graph play a special role in the structure of the truncated powers and partition functions that are associated with the graph ...
Ron, Amos, Shengnan, Wang
core  

Sub-exponential Time Parameterized Algorithms for Graph Layout Problems on Digraphs with Bounded Independence Number. [PDF]

Algorithmica, 2023
Misra P, Saurabh S, Sharma R, Zehavi M.
europepmc   +1 more source