## Abstract Let __r__~__k__~(__G__) be the __k__โcolor Ramsey number of a graph __G__. It is shown that $r\_{k}(C\_{5})\le \sqrt{18^{k}\,k!}$ for __k__โฉพ2 and that __r__~__k__~(__C__~2__m__+ 1~)โฉฝ(__c__^__k__^__k__!)^1/__m__^ if the Ramsey graphs of __r__~__k__~(__C__~2__m__+ 1~) are not far away fr
The chromatic Ramsey number of odd wheels
โ Scribed by Nathalie Paul; Claude Tardif
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 110 KB
- Volume
- 69
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
โฆ Synopsis
We prove that the chromatic Ramsey number of every odd wheel W 2k+1 , k โฅ 2 is 14. That is, for every odd wheel W 2k+1 , there exists a 14-chromatic graph F such that when the edges of F are two-coloured, there is a monochromatic copy of W 2k+1 in F, and no graph F with chromatic number 13 has the same property. We ask whether a natural extension of odd wheels to the family of generalized Mycielski graphs could help to prove the Burr-Erd os-Lovรกsz conjecture on the minimum possible chromatic Ramsey number of an n-chromatic graph.
๐ SIMILAR VOLUMES
## Abstract We investigate the asymptotics of the size Ramsey number __รฎ__(__K__~1,__n__~__F__), where __K__~1,__n__~ is the __n__โstar and __F__ is a fixed graph. The author 11 has recently proved that __rฬ__(__K__~1,n~,__F__)=(1+__o__(1))__n__^2^ for any __F__ with chromatic number ฯ(__F__)=3. He
## Abstract Let __G__ be a nonโbipartite graph with โ as the length of the longest odd cycle. Erdรถs and Hajnal proved that ฯ(__G__) โค โ + 1. We show that the only graphs for which this is tight are those that contain __K__~โ~ + 1 and further, if __G__ does not contain __K__~โ~ then ฯ(__G__) โค โ โ1.
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