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Rainbow ramsey numbers

Posted on:2001-02-09Degree:Ph.DType:Dissertation
University:Western Michigan UniversityCandidate:Eroh, Linda LouiseFull Text:PDF
GTID:1460390014958192Subject:Mathematics
Abstract/Summary:PDF Full Text Request
We investigate a new generalization of the generalized ramsey number for graphs. Recall that the generalized ramsey number for graphs G1, G2,…, Gc is the minimum positive integer N such that any coloring of the edges of the complete graph KN with c colors must contain a subgraph isomorphic to Gi in color i for some i. Bialostocki and Voxman defined RM(G) for a graph G to be the minimum N such that any edge-coloring of KN with any number of colors must contain a subgraph isomorphic to G in which either every edge is the same color (a monochromatic G) or every edge is a different color (a rainbow G). This number exists if and only if G is acyclic.; Expanding on this definition, we define the rainbow ramsey number RR(G1, G 2) of graphs G1 and G 2 to be the minimum N such that any edge-coloring of KN with any number of colors contains either a monochromatic G1 or a rainbow G2. This number exists if and only if G1 is a star or G2 is acyclic. We present upper and lower bounds for RR(K1,n, Km), RR(Kn, Tm), RR(Kn, K m), RR(K1, n, mK2) and RR(nK 2, K1,m, where Tm is an arbitrary tree of order m.; We also define the edge-chromatic ramsey number CR(G1,G2) to be the minimum N such that any edge-coloring of KN must contain either a monochromatic G 1 or a properly edge-colored G2. When both are defined, CR(G1, G2) ≤ RR(G1 , G2). We consider bounds for CR (Cn, Pm), CR( K1,n, Pm), CR(Pn, Pm), and the corresponding rainbow ramsey numbers.; These two new ramsey numbers can be further generalized as the F -free ramsey number. For a set of graphs F , an F -free coloring of a graph G is a coloring so that G does not contain any monochromatic subgraph isomorphic to any graph in F . The F -free ramsey number of graphs G 1 and G2, denoted RF (G1, G2), is the minimum N such that every edge-coloring of KN contains either a monochromatic copy of G
Keywords/Search Tags:Ramsey number, Such that any edge-coloring, Monochromatic, Graphs, Minimum
PDF Full Text Request
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