A new construction of self-complementary graphs containing no Klo or K , is described. This construction gives the Ramsey number lower bounds r(10,lO) 2 458 and r(1 1,l 1 ) 2 542. The problem of determining the Ramsey numbers is known to be very difficult and so we are often satisfied with partial
Tidier Examples for Lower Bounds on Diagonal Ramsey Numbers
โ Scribed by Colin McDiarmid; Angelika Steger
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 266 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0097-3165
No coin nor oath required. For personal study only.
โฆ Synopsis
There is a family (H k ) of graphs such that H k has order (1+o(1))(-2รe) k 2 kร2 but has no clique or stable set of order k. This result of Spencer provides the best known lower bound for the diagonal Ramsey numbers R(k, k). Here we see that the graphs H k can be taken to be regular, self-complementary, and pseudo-random.
๐ SIMILAR VOLUMES
## Abstract For any graph __G__, let __i__(__G__) and ฮผ;(__G__) denote the smallest number of vertices in a maximal independent set and maximal clique, respectively. For positive integers __m__ and __n__, the lower Ramsey number __s__(__m, n__) is the largest integer __p__ so that every graph of or
## dedicated to the memory of rodica simion Let G be an r-uniform hypergraph. The multicolor Ramsey number r k G is the minimum n such that every k-coloring of the edges of the complete r-uniform hypergraph K r n yields a monochromatic copy of G. Improving slightly upon results from M. Axenovich,
The multicolor Ramsey number r k (C 4 ) is the smallest integer n for which any k-coloring of the edges of the complete graph K n must produce a monochromatic 4-cycle. It was proved earlier that r k (C 4 ) k 2 &k+2 for k&1 being a prime power. In this note we establish r k (C 4 ) k 2 +2 for k being