Browse > Article
http://dx.doi.org/10.9708/jksci.2015.20.3.069

Experimental Proof for Symmetric Ramsey Numbers  

Lee, Sang-Un (Dept. of Multimedia Eng., Gangneung-Wonju National University)
Abstract
This paper offers solutions to unresolved $43{\leq}R(5,5){\leq}49$ and $102{\leq}R(6,6){\leq}165$ problems of Ramsey's number. The Ramsey's number R(s,t) of a complete graph $k_n$ dictates that n-1 number of incidental edges of a arbitrary vertex ${\upsilon}$ is dichotomized into two colors: (n-1)/2=R and (n-1)/2=B. Therefore, if one introduces the concept of distance to the vertex ${\upsilon}$, one may construct a partite graph $K_n=K_L+{\upsilon}+K_R$, to satisfy (n-1)/2=R of {$K_L,{\upsilon}$} and (n-1)/2=B of {${\upsilon},K_R$}. Subsequently, given that $K_L$ forms the color R of $K_{s-1)$, $K_S$ is attainable. Likewise, given that $K_R$ forms the color B of $K_{t-1}$, $K_t$ is obtained. By following the above-mentioned steps, $R(s,t)=K_n$ was obtained, satisfying necessary and sufficient conditions where, for $K_L$ and $K_R$, the maximum distance should be even and incidental edges of all vertices should be equal are satisfied. This paper accordingly proves R(5,5)=43 and R(6,6)=91.
Keywords
Ramsey number; Partite graph; Distance; Degree;
Citations & Related Records
연도 인용수 순위
  • Reference
1 F. P. Ramsey, "On a Problem of Formal Logic," Proceedings of London Mathematics, Series 2, Vol. 30, pp. 264-286, 1930.
2 Wikipedia, "Ramsey Theory," http://en.wikipedia.org/wiki/Ramsey_theory, Wikimedia Foundation Inc., 2014.
3 Wikipedia, "Ramsey's Theorem," http://en.wikipedia.org/wiki/Ramsey's_theorem, Wikimedia Foundation Inc., 2014.
4 E. W. Weisstein, "Ramsey's Theorem" http://mathworld.wolfram.com/RamseysTheorem.html, MathWorld, Wolfram Research, Inc., 2014.
5 E. W. Weisstein, "Ramsey Number" http://mathworld.wolfram.com/RamseyNumber.html, MathWorld, Wolfram Research, Inc., 2014.
6 Wikipedia, "Theorem on Friends and Strangers," http://en.wikipedia.org/wiki/Theorem_on_friends_and_strangers, Wikimedia Foundation Inc., 2014.
7 Wikipedia, "Pigeonhole Principle," http://en.wikipedia.org/wiki/Pigonhole_principle, Wikimedia Foundation Inc., 2014.
8 G. E. W. Taylor, "Ramsey Theory," School of Mathematics, The University of Birmingham, 2006.
9 Math Explorers' Club, "Howto Play Ramsey Graph Games," Math Explorers' Club, Cornell Department of Mathematics, 2004.
10 I. Leader, "Friends and Strangers," Millenium Mathematics Project, University of Cambridge, 2001.
11 B. D. McKay and S. P. Radziszowski, "Subgraph Counting Identities and Ramsey Numbers," Journal of Combinatorial Theory, Series B, Vol. 69, No. 2, pp. 193-209, Mar. 1997.   DOI   ScienceOn
12 C. J. Kunkel and P. Ng, "RamseyNumbers: Improving the Bounds of R(5,5)," Midwest Instruction and Computing Symposium (MICS), 2003.
13 Z. Bian, F. Chudak,W.G.Macready, L. Clark, and F. Gaitan, "Experimental Determination of Ramsey Numbers," Physical ReviewLetters, Vol. 111, No. 13, pp. 1-6, Sep. 2013.
14 X. Xiaodong, X. Zheng, G. Exoo, and S. P. Radziszowski, "Constructive Lower Bounds on Classical Multicolor Ramsey Numbers," Electronic Journal of Combinatorics, Vol. 11, No. 1, pp. 1-24, Jan. 2004.
15 J. A. Bondy andU. S. R.Murty, "Graduate Texts in Mathematics: Graph Theory," Springer-Verlag, 2006.