The maximal clique and colourability of curve contact graphs Original Research Article

Contact graphs are a special kind of intersection graphs of geometrical objects in which the objects are not allowed to cross but only to touch each other. Contact graphs of simple curves, and line segments as a special case, in the plane are considered. The curve contact representations are studied with respect to the maximal clique and the chromatic number of the represented graphs. All possible curve contact representations of cliques are described, and a linear bound on chromatic number in the maximal clique size is proved for the curve contact graphs.