Improved bounds for the chromatic index of graphs and multigraphs
โ Scribed by Hakimi, S. Louis; Schmeichel, Edward F.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 321 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0364-9024
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โฆ Synopsis
We show that coloring the edges of a multigraph G in a particular order often leads to improved upper bounds for the chromatic index ฯ (G). Applying this to simple graphs, we significantly generalize recent conditions based on the core of G (i.e., the subgraph of G induced by the vertices of degree โ(G)), which insure that ฯ (G) = โ(G). Finally, we show that ฯ (G) โค โ(G) + ยต(G) in any multigraph G in which every cycle of length larger than 2 contains a simple edge, where ยต(G) is the largest edge multiplicity in G.
๐ SIMILAR VOLUMES
Let G = (V, E) be a graph and let k be a nonnegative integer. A vector c โ Z V + is called k-colorable iff there exists a coloring of G with k colors that assigns exactly c(v) colors to vertex v โ V . Denote by ฯ(G) and ฯ f (G) the chromatic number and fractional chromatic number, respectively. We p
Consider a 2-dimensional consecutive-k-out-of-n : F system, as described by Salvia and Lasher [9], whose components have independent, perhaps identical, failure probabilities. In this paper, we use Janson's exponential inequalities to derive improved upper bounds on such a system's reliability, and