Results 21 to 30 of about 4,954 (163)
Characterizing extremal digraphs for identifying codes and extremal cases of Bondy's theorem on induced subsets [PDF]
, 2012 An identifying code of a (di)graph $G$ is a dominating subset $C$ of the vertices of $G$ such that all distinct vertices of $G$ have distinct (in)neighbourhoods within $C$.
A. Winter +15 more
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Some Fixed Point Theorems in Modular Function Spaces Endowed with a Graph
Abstract and Applied Analysis, 2020 The aim of this paper is to give fixed point theorems for G-monotone ρ-nonexpansive mappings over ρ-compact or ρ-a.e. compact sets in modular function spaces endowed with a reflexive digraph not necessarily transitive.
Jaauad Jeddi +2 more
doaj +1 more source
(, )-kernels and Sands, Sauer and Woodrow’s theorem
AKCE International Journal of Graphs and Combinatorics, 2019 Let = ( (), ()) a digraph. Consider the set = { : is a non trivial finite directed path in } and let and two subsets of . A subset of () is said to be an (, )-kernel of if (1) for every subset {, } of there exists no -directed path such that ( is ...
Hortensia Galeana-Sánchez +2 more
doaj +2 more sources
Semi-Transitive Orientations and Word-Representable Graphs [PDF]
, 2015 A graph $G=(V,E)$ is a \emph{word-representable graph} if there exists a word $W$ over the alphabet $V$ such that letters $x$ and $y$ alternate in $W$ if and only if $(x,y)\in E$ for each $x\neq y$.
Halldórsson, Magnús M. +2 more
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Kings in quasi-transitive digraphs
Discrete Mathematics, 1998 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Bang-Jensen, Jørgen, Huang, Jing
openaire +3 more sources
Constructions for arc-transitive digraphs [PDF]
Journal of the Australian Mathematical Society. Series A. Pure Mathematics and Statistics, 1995 AbstractA number of constructions are given for arc-transitive digraphs, based on modifications of permutation representations of finite groups. In particular, it is shown that for every positive integer s and for any transitive permutation group p of degree k, there are infinitely many examples of a finite k-regular digraph with a group of ...
Conder, Marston +2 more
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Vertex-quasiprimitive 2-arc-transitive digraphs
Ars Mathematica Contemporanea, 2017 We study vertex-quasiprimitive $2$-arc-transitive digraphs, reducing the problem of vertex-primitive $2$-arc-transitive digraphs to almost simple groups. This includes a complete classification of vertex-quasiprimitive $2$-arc-transitive digraphs where the action on vertices has O'Nan-Scott type SD or CD.
Giudici, Michael, Xia, Binzhou
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Strongly connectable digraphs and non-transitive dice
AKCE International Journal of Graphs and Combinatorics, 2020 We give a new proof of the theorem of Boesch–Tindell and Farzad–Mahdian–Mahmoodian–Saberi–Sadri that a directed graph extends to a strongly connected digraph on the same vertex set if and only if it has no complete directed cut.
Simon Joyce +3 more
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Extremal Digraphs Avoiding Distinct Walks of Length 4 with the Same Endpoints
Discussiones Mathematicae Graph Theory, 2022 Let n ≥ 8 be an integer. We characterize the extremal digraphs of order n with the maximum number of arcs avoiding distinct walks of length 4 with the same endpoints.
Lyu Zhenhua
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Journal of Physics: Conference Series, 2020 Abstract In the present paper the class of digraph groups is introduced by analogy with the prominent class of “graph groups”. Digraph groups implicitly present in the previous work by the author on the automorphism groups of graph groups. The structure of transitive digraph groups is described in terms of the Levi decomposition into the
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