Results 61 to 70 of about 1,634 (112)

Distinguishing tournaments with small label classes [PDF]

open access: yes, 2019
A d-distinguishing vertex (arc) labeling of a digraph is a vertex (arc) labeling using d labels that is not preserved by any nontrivial automorphism. Let ρ(T) (ρ′(T)) be the minimum size of a label class in a 2-distinguishing vertex (arc) labeling of a ...
Lozano Bojados, Antoni
core   +1 more source

Coverings of Cubic Graphs and 3-Edge Colorability

open access: yesDiscussiones Mathematicae Graph Theory, 2021
Let h:G˜→Gh:\tilde G \to G be a finite covering of 2-connected cubic (multi)graphs where G is 3-edge uncolorable. In this paper, we describe conditions under which G˜\tilde G is 3-edge uncolorable. As particular cases, we have constructed regular and
Plachta Leonid
doaj   +1 more source

The $(k,\ell)$-rainbow index of random graphs [PDF]

open access: yes, 2013
A tree in an edge colored graph is said to be a rainbow tree if no two edges on the tree share the same color. Given two positive integers $k$, $\ell$ with $k\geq 3$, the \emph{$(k,\ell)$-rainbow index} $rx_{k,\ell}(G)$ of $G$ is the minimum number of ...
Cai, Qingqiong   +2 more
core  

On Proper (Strong) Rainbow Connection of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A path in an edge-colored graph G is called a rainbow path if no two edges on the path have the same color. The graph G is called rainbow connected if between every pair of distinct vertices of G, there is a rainbow path.
Jiang Hui   +3 more
doaj   +1 more source

On Local Antimagic Chromatic Number of Cycle-Related Join Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
An edge labeling of a connected graph G = (V, E) is said to be local antimagic if it is a bijection f : E → {1, . . ., |E|} such that for any pair of adjacent vertices x and y, f+(x) ≠ f+(y), where the induced vertex label f+(x) = Σf(e), with e ranging ...
Lau Gee-Choon, Shiu Wai-Chee, Ng Ho-Kuen
doaj   +1 more source

Coloring subgraphs with restricted amounts of hues

open access: yesOpen Mathematics, 2017
We consider vertex colorings where the number of colors given to specified subgraphs is restricted. In particular, given some fixed graph F and some fixed set A of positive integers, we consider (not necessarily proper) colorings of the vertices of a ...
Goddard Wayne, Melville Robert
doaj   +1 more source

The Distinguishing Number and Distinguishing Index of the Lexicographic Product of Two Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2018
The distinguishing number (index) D(G) (D′(G)) of a graph G is the least integer d such that G has a vertex labeling (edge labeling) with d labels that is preserved only by the trivial automorphism.
Alikhani Saeid, Soltani Samaneh
doaj   +1 more source

Neighbor Sum Distinguishing Total Choosability of IC-Planar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2020
Two distinct crossings are independent if the end-vertices of the crossed pair of edges are mutually different. If a graph G has a drawing in the plane such that every two crossings are independent, then we call G a plane graph with independent crossings
Song Wen-Yao   +2 more
doaj   +1 more source

2-Distance Colorings of Integer Distance Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2019
A 2-distance k-coloring of a graph G is a mapping from V (G) to the set of colors {1,. . ., k} such that every two vertices at distance at most 2 receive distinct colors.
Benmedjdoub Brahim   +2 more
doaj   +1 more source

Facial Rainbow Coloring of Plane Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2019
A vertex coloring of a plane graph G is a facial rainbow coloring if any two vertices of G connected by a facial path have distinct colors. The facial rainbow number of a plane graph G, denoted by rb(G), is the minimum number of colors that are necessary
Jendroľ Stanislav, Kekeňáková Lucia
doaj   +1 more source

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