Semester

Summer

Date of Graduation

2000

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Lane Department of Computer Science and Electrical Engineering

Committee Chair

Elaine Eschen.

Abstract

Let G = (V, E) be a simple graph. The clique hypergraph of G, denoted as CH( G), has V as its set of vertices, and the maximal cliques as its hyperedges. Let Sk be a set of k colors. A map c : V Sk is a proper k-coloring for CH(G) if any maximal clique of G with at least two vertices receives at least two distinct colors. Let W ⊂ V, and let s ≥ 1. We say that G is (W, s)-extendible if any assignment on W with at most s colors can be extended to a proper s-coloring of CH(G). We prove that the clique hypergraphs of chordal and comparability graphs are bicolorable and that the clique hypergraphs of circular-arc graphs are 3-colorable. Our main result is the characterization of (W, 2)-extendibility for chordal graphs in the case when W=2 .

Share

COinS