Connected Colorings of Graphs

Yair Caro1, Yehuda Roditty2
1Departinent of Mathematics School of Education University of Haifa ~ ORANIM Ticou ISRAEL 36910
2School of Computer Sciences, Tel Aviv University, Tel Aviv 69978, Israel and Departinent of Computer Science, The Academie College of Tet-Aviv-Yallo, Tel-Aviv G11GL, Israel

Abstract

Let \(H = K_{k_1,k_2,\ldots,k_t}\) be a complete multipartite graph having \(t \geq 3\) parts. Extending the well-known result that a simple graph \(G\) or its complement, \({G}\), is connected, it is proved that in any coloring of the edges of \(H\) with two colors, blue and red, at least one of the subgraphs induced by the blue edges or by the red edges, is connected.