Hanna Furmańczyk EQUITABLE COLORING OF GRAPH PRODUCTS

A graph is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the number of vertices in any two sets differ by at most one. The smallest k for which such a coloring exists is known as the equitable chromatic number of G and denoted by χ=(G). It is interesting to note that if a graph G is equitably k-colorable, it does not imply that it is equitably (k + 1)-colorable. The smallest integer k for which G is equitably k′-colorable for all k′ ≥ k is called the equitable chromatic threshold of G and denoted by χ∗=(G). In the paper we establish the equitable chromatic number and the equitable chromatic threshold for certain products of some highly-structured graphs. We extend the results from [2] for Cartesian, weak and strong tensor products.