An upper bound for the Ramsey numbers r(K3,G)
β Scribed by Wayne Goddard; Daniel J. Kleitman
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 372 KB
- Volume
- 125
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
The Ramsey number r(H, G) is defined as the minimum N such that for any coloring of the edges of the N-vertex complete graph KN in red and blue, it must contain either a ted H or a blue G. In this paper we show that for any graph G without isolated vertices, r(K,, G)< 2qf 1 where G has q edges. In other words, any graph on 2q+ 1 vertices with independence number at most 2 contains every (isolate-free) graph on q edges. This establishes a 1980 conjecture of Harary. The result is best possible as a function of q.
π SIMILAR VOLUMES
New upper bounds for the ramsey numbers r ( k , I ) are obtained. In particular it is shown there is a constant A such that The ramsey number r(k, l ) is the smallest integer n, such that any coloring with red and blue of the edges of the complete graph K , of order n yields either a red K , subgra
In this paper we show that for n β₯ 4, R(3, 3, . . . , 3) < n!( e-e -1 + 3 2 ) + 1. Consequently, a new bound for Schur numbers is also given. Also, for even n β₯ 6, the Schur number S n is bounded by S n < n!( e-e -1 + 3 2 ) -n + 2.
## Abstract Harary stated the conjecture that for any graph __G__ with __n__ edges and without isolated vertices __r__(__K__~3~,__G__) β©½ 2__n__ + 1. ErdΓΆs, Faudree, Rousseau, and Schelp proved that __r__(__K__~3~,__G__) β©½ β8/3__n__β. Here we prove that __r__(__K__~3~,__G__) β©½ β5/2__n__β β1 for __n_
The Ramsey number N(3, 3, 3, 3; 2) is the smallest integer n such that each 4-coloring by edges of the complete graph on n vertices contains monochromatic triangles. It is well known that 51 ~< N(3,3,3,3;2) ~< 65. Here we prove that N(3,3,3,3;2) ~< 64.