Results 11 to 20 of about 16,499 (231)
AKCE International Journal of Graphs and Combinatorics, 2020 Let and be two digraphs; without loops or multiple arcs. An coloring of is a function . We say that is an colored digraph. For an arc of , we say that is the color of over the coloring . A directed path in is an path if is a directed walk in .
Hortensia Galeana-Sánchez +1 more
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Digraph Decompositions and Monotonicity in Digraph Searching [PDF]
Theoretical Computer Science, 2008 We consider monotonicity problems for graph searching games. Variants of these games - defined by the type of moves allowed for the players - have been found to be closely connected to graph decompositions and associated width measures such as path- or tree-width. Of particular interest is the question whether these games are monotone, i.e. whether the
Stephan Kreutzer, Sebastian Ordyniak
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On Packing Dijoins in Digraphs and Weighted Digraphs
SIAM Journal on Discrete Mathematics, 2023 Let $D=(V,A)$ be a digraph. A dicut is a cut $δ^+(U)\subseteq A$ for some nonempty proper vertex subset $U$ such that $δ^-(U)=\emptyset$, a dijoin is an arc subset that intersects every dicut at least once, and more generally a $k$-dijoin is an arc subset that intersects every dicut at least $k$ times.
Ahmad Abdi +2 more
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The Electronic Journal of Combinatorics, 2011 We study digraphs preserved by a Maltsev operation: Maltsev digraphs. We show that these digraphs retract either onto a directed path or to the disjoint union of directed cycles, showing in this way that the constraint satisfaction problem for Maltsev digraphs is in logspace, L.
Catarina Carvalho +3 more
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Iota energy of weighted digraphs [PDF]
Transactions on Combinatorics, 2018 The eigenvalues of a digraph are the eigenvalues of its adjacency matrix. The iota energy of a digraph is recently defined as the sum of absolute values of imaginary part of its eigenvalues. In this paper, we extend the concept of iota energy of digraphs
Sumaira Hafeez, Mehtab Khan
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On Single Valued Neutrosophic Signed Digraph and its applications [PDF]
Neutrosophic Sets and Systems, 2018 The development of the theory of the single valued neutrosophic (SVN) digraph is done in this paper. Also this paper introduces the concept of SVN signed digraph.
K. Sinha, P. Majumdar
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A new kind of Hermitian matrices for digraphs [PDF]
Linear Algebra and its Applications, 2019 In an earlier work, the author together with Guo [Hermitian adjacency matrix of digraphs and mixed graphs, J. Graph Theory 85 (2017) 217-248] introduced the Hermitian adjacency matrix of directed (and partially directed) graphs.
B. Mohar
semanticscholar +1 more source
A note on the Roman domatic number of a digraph [PDF]
Communications in Combinatorics and Optimization, 2020 A {\em Roman dominating function} on a digraph $D$ with vertex set $V(D)$ is a labeling $f\colon V(D)\to \{0, 1, 2\}$ such that every vertex with label $0$ has an in-neighbor with label $2$. A set $\{f_1,f_2,\ldots,f_d\}$ of Roman dominating functions
Lutz Volkmann, D. Meierling
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Resolvable Networks—A Graphical Tool for Representing and Solving SAT
Mathematics, 2021 In this paper, we introduce the notion of resolvable networks. A resolvable network is a digraph of subnetworks, where subnetworks may overlap, and the inner structure of subnetworks are not interesting from the viewpoint of the network.
Gábor Kusper, Csaba Biró, Benedek Nagy
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