Results 61 to 70 of about 1,606 (89)
Conflict-Free Vertex Connection Number At Most 3 and Size of Graphs
Discussiones Mathematicae Graph Theory, 2021 A path in a vertex-coloured graph is called conflict-free if there is a colour used on exactly one of its vertices. A vertex-coloured graph is said to be conflict-free vertex-connected if any two distinct vertices of the graph are connected by a conflict-
Doan Trung Duy, Schiermeyer Ingo
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An Improved Upper Bound on Neighbor Expanded Sum Distinguishing Index
Discussiones Mathematicae Graph Theory, 2020 A total k-weighting f of a graph G is an assignment of integers from the set {1, . . . , k} to the vertices and edges of G. We say that f is neighbor expanded sum distinguishing, or NESD for short, if Σw∈N(v) (f(vw) + f(w)) differs from Σw∈N(u)(f(uw) + f(
Vučković Bojan
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Note on group irregularity strength of disconnected graphs
Open Mathematics, 2018 We investigate the group irregularity strength (sg(G)) of graphs, i.e. the smallest value of s such that taking any Abelian group 𝓖 of order s, there exists a function f : E(G) → 𝓖 such that the sums of edge labels at every vertex are distinct. So far it
Anholcer Marcin +3 more
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More on the Minimum Size of Graphs with Given Rainbow Index
Discussiones Mathematicae Graph Theory, 2020 The concept of k-rainbow index rxk(G) of a connected graph G, introduced by Chartrand et al., is a natural generalization of the rainbow connection number of a graph.
Zhao Yan
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Disproof of the List Hadwiger Conjecture
, 2011 The List Hadwiger Conjecture asserts that every $K_t$-minor-free graph is $t$-choosable. We disprove this conjecture by constructing a $K_{3t+2}$-minor-free graph that is not $4t$-choosable for every integer $t\geq 1$
Barát, János +2 more
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Sum-List Colouring of Unions of a Hypercycle and a Path with at Most Two Vertices in Common
Discussiones Mathematicae Graph Theory, 2020 Given a hypergraph and a function f : V () → , we say that is f-choosable if there is a proper vertex colouring ϕ of such that ϕ (v) ∈ L(v) for all v ∈ V (), where L : V () → 2 is any assignment of f(v) colours to a vertex v.
Drgas-Burchardt Ewa +1 more
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On Nordhaus-Gaddum type relations of δ-complement graphs. [PDF]
Heliyon, 2023 Vichitkunakorn P +2 more
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Maximum Edge-Colorings Of Graphs
Discussiones Mathematicae Graph Theory, 2016 An r-maximum k-edge-coloring of G is a k-edge-coloring of G having a property that for every vertex v of degree dG(v) = d, d ≥ r, the maximum color, that is present at vertex v, occurs at v exactly r times. The r-maximum index χr′(G)$\chi _r^\prime (G)$
Jendrol’ Stanislav +1 more
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Facial Incidence Colorings of Embedded Multigraphs
Discussiones Mathematicae Graph Theory, 2019 Let G be a cellular embedding of a multigraph in a 2-manifold. Two distinct edges e1, e2 ∈ E(G) are facially adjacent if they are consecutive on a facial walk of a face f ∈ F(G). An incidence of the multigraph G is a pair (v, e), where v ∈ V (G), e ∈ E(G)
Jendrol’ Stanislav +2 more
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Tr-Span of Directed Wheel Graphs
Discussiones Mathematicae Graph Theory, 2018 In this paper, we consider T-colorings of directed graphs. In particular, we consider as a T-set the set Tr = {0, 1, 2, . . ., r−1, r+1, . . .}. Exact values and bounds of the Tr-span of directed graphs whose underlying graph is a wheel graph are ...
Besson Marc, Tesman Barry
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