Results 71 to 80 of about 1,773 (109)
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
doaj +1 more source
On Nordhaus-Gaddum type relations of δ-complement graphs. [PDF]
Heliyon, 2023 Vichitkunakorn P +2 more
europepmc +1 more source
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
doaj +1 more source
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
doaj +1 more source
Application of maple on computing strong fuzzy chromatic polynomial of fuzzy graphs. [PDF]
BMC Res Notes, 2022 Ashebo MA, Rathour L, Repalle VNS.
europepmc +1 more source
List Star Edge-Coloring of Subcubic Graphs
Discussiones Mathematicae Graph Theory, 2018 A star edge-coloring of a graph G is a proper edge coloring such that every 2-colored connected subgraph of G is a path of length at most 3. For a graph G, let the list star chromatic index of G, ch′st(G), be the minimum k such that for any k-uniform ...
Kerdjoudj Samia +2 more
doaj +1 more source
The complexity of frugal colouring. [PDF]
Arab J Math, 2021 Bard S, MacGillivray G, Redlin S.
europepmc +1 more source
On Generalized Sierpiński Graphs
Discussiones Mathematicae Graph Theory, 2017 In this paper we obtain closed formulae for several parameters of generalized Sierpiński graphs S(G, t) in terms of parameters of the base graph G. In particular, we focus on the chromatic, vertex cover, clique and domination numbers.
Rodríguez-Velázquez Juan Alberto +2 more
doaj +1 more source