Title
The 3-rainbow index of a graph.
Abstract
Let G be a nontrivial connected graph with an edge-coloring c: E(G) -> {1, 2, ... , q}, q is an element of N, where adjacent edges may be colored the same. A tree T in G is a rainbow tree if no two edges of T receive the same color. For a vertex subset S subset of V(G), a tree that connects S in G is called an S-tree. The minimum number of colors that are needed in an edge-coloring of G such that there is a rainbow S-tree for each k-subset S of V(G) is called the k-rainbow index of G, denoted by rx(k)(G). In this paper, we first determine the graphs of size m whose 3-rainbow index equals m, m - 1, m - 2 or 2. We also obtain the exact values of rx(3)(G) when G is a regular multipartite complete graph or a wheel. Finally, we give a sharp upper bound for rx(3)(G) when G is 2-connected and 2-edge connected. Graphs G for which rx(3)(G) attains this upper bound are determined.
Year
DOI
Venue
2015
10.7151/dmgt.1780
DISCUSSIONES MATHEMATICAE GRAPH THEORY
Keywords
Field
DocType
rainbow tree,S-tree,k-rainbow index
Graph,Discrete mathematics,Combinatorics,Multipartite,Vertex (geometry),Upper and lower bounds,Bipartite graph,Connectivity,Rainbow,Mathematics
Journal
Volume
Issue
ISSN
35
1
1234-3099
Citations 
PageRank 
References 
5
0.78
4
Authors
4
Name
Order
Citations
PageRank
Lily Chen1496.36
Xueliang Li2737103.78
Kang Yang37819.31
Yan Zhao492.63