Caro, Y., On zero-sum Ramsey numbers--stars, Discrete Mathematics 104 (1992) l-6. Let n 3 k 2 2 be positive integers, k ( n. Let H, be the cyclic group of order k. Denote by R(K,,,> Z,) the minimal integer t such that for every &-coloring of the edges of K,, (i.e., a function c : E(K,)+ hk), there i
On three zero-sum Ramsey-type problems
✍ Scribed by Noga Alon; Yair Caro
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 821 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
For a graph G whose number of edges is divisible by k, let R(G,Z~k~) denote the minimum integer r such that for every function f: E(K~r~) ↦ Z~k~ there is a copy G^1^ of G in K~r~ so that Σe∈E(G^1^) f(e) = 0 (in Z~k~). We prove that for every integer k~1~ R(K~n~, Z~k~) ≤ n + O(k^3^ log k) provided n is sufficiently large as a function of k and k divides (). If, in addition, k is an odd prime‐power then R(K~n~, Z~k~) ≤ n + 2__k__ ‐ 2 and this is tight if k is a prime that divides n. A related result is obtained for hypergraphs. It is further shown that for every graph G on n vertices with an even number of edges R(G,Z~2~) ≤ n + 2. This estimate is sharp. © 1993 John Wiley & Sons, Inc.
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