H-Factors in Dense Graphs Raphael Yuster Summary: H-Factors in Dense Graphs Noga Alon and Raphael Yuster Department of Mathematics Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University, Tel Aviv, Israel Abstract The following asymptotic result is proved. For every > 0, and for every positive integer h, there exists an n0 = n0( , h) such that for every graph H with h vertices and for every n > n0, any graph G with hn vertices and with minimum degree d ((H)-1 (H) + )hn contains n vertex disjoint copies of H. This result is asymptotically tight and its proof supplies a polynomial time algorithm for the corresponding algorithmic problem. 1 Introduction All graphs considered here are finite, undirected and simple. If H is a graph on h vertices and G is a graph on hn vertices, we say that G has an H-factor if it contains n vertex disjoint copies of H. Thus, for example, a K2-factor is simply a perfect matching, whereas a C4-factor is a spanning subgraph of G every connected component of which is a cycle of length 4. Let H be a graph on h vertices and let G be a graph on hn vertices. There are several known Collections: Mathematics