Indexed by:
Abstract:
The notion of goodness for Ramsey numbers was introduced by Burr and Erds in 1983. For graphs G and H, let G + H be the graph obtained from disjoint G and H by adding all edges between the vertices of G and H. Denote nH by the union of n disjoint copies of H. Let Bn(k) = Kk + nK1, which is called a book. We first obtain that if t ≥ 1 and k ≥ 2 are fixed integers and G is a fixed graph, then for all large n, r(K1,t + G, Bn(k)) ≤ (χ (G) + 1)(n + kt - 1) + 1. This is sharp for several classes of graphs. Faudree, Rousseau, and Sheehan in 1978 proved that q2 + q + 2 ≤ r(C4, Bq(2)2- q+1) ≤ q2 + q + 4 for prime power q, which implies that Bn(2) is not C4good for q2 - q + 1 ≤ n ≤ q2 + q. It is very difficult to determine the exact values for r(C4, Bn(2)). Moreover, Nikiforov and Rousseau in 2009 already proved that Bn(k) is (K2 + C4)-good for fixed k ≥ 2 and large n. In this paper, we obtain that for fixed k ≥ 2 and large n, r(K1 + C4, Bn (k)) = (Equation presented). This implies that Bn(k) is not (K1 +C4)-good for each fixed k ≥ 2. © 2021 Society for Industrial and Applied Mathematics.
Keyword:
Reprint 's Address:
Email:
Source :
SIAM Journal on Discrete Mathematics
ISSN: 0895-4801
Year: 2021
Issue: 1
Volume: 35
Page: 23-34
0 . 8 6 8
JCR@2021
0 . 9 0 0
JCR@2023
ESI HC Threshold:105
JCR Journal Grade:4
CAS Journal Grade:4
Cited Count:
SCOPUS Cited Count: 10
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 1
Affiliated Colleges: