作者: G. R. Brightwell , Y. Kohayakawa
关键词: Combinatorics 、 Graph 、 Discrete mathematics 、 Gallai–Hasse–Roy–Vitaver theorem 、 Binary logarithm 、 Paley graph 、 Digraph 、 Mathematics 、 Acyclic orientation
摘要: A classical result of Rodl (in Graphs, Hypergraphs and Block Systems, 1976, pp. 211 to 220) says that for any acyclic digraph D there is a graph G = G(D) such every orientation contains an induced copy D. recent Winkler (SIAM J. Discrete Math., 2: 402–406, 1989) implies order O(n3 (log n)2), where n |D| the Here we show by probabilistic means almost Gn [(4/9)n2n/2] has property on vertices. We also be greater than (1/10)n2n/2. Thus our results are essentially best possible. Moreover, Paley graphs O(n24n) having above. consider some problems raised Cochand Duchet (Irregularities Partitions, Springer-Verlag, Berlin, 1989, 39–46.) related topics. © 1993 John Wiley & Sons, Inc.