THE RAMSEY NUMBERS FOR DISJOINT UNION OF STARS

Abstract: The Ramsey number for a graph G versus a graph H, denoted by R(G; H), is the smallest positive integer n such that for any graph F of order n,either F contains G as a subgraph or F contains H as a subgraph. In this paper, we investigate the Ramsey numbers for union of stars versus small cycle and small wheel. We show that if ni ≥ 3 for i = 1; 2; : : : ; k and ni ≥ ni+1 ≥ pni − 2, then R(Sk i=1 S1+ni; C4) = Pk i=1 ni + k + 1 for k ≥ 2. Furthermore, we show that if ni is odd and 2ni+1 ≥ ni for every i, then R(Sk i=1 Sni; W4) = R(Snk; W4) + Pk i=1 −1 ni for k ≥ 1:
Key words and Phrases: Ramsey number, cycle, wheel
Author: Hasmawati
Journal Code: jpmatematikagg100014

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