English

An explicit Ramsey graph

Combinatorics 2015-01-06 v2

Abstract

Explicit construction of Ramsey graphs has remained a challenging open problem for a long time. Frankl--Wilson \cite{FW}, Alon \cite{A} and Grolmusz \cite{G2} gave the best explicit constructions of graphs on mm vertices with no clique or independent set of size m(1+o(1))14logmloglogmm^{(1+o(1))\frac{1}{4}\frac{\log m}{\log \log m}}. We describe here an explicit construction which produces for every integer m>1m>1 a graph on at least m(1+o(1))13logmloglogmm^{(1+o(1))\frac{1}{3}\frac{\log m}{\log \log m}} vertices containing neither a clique of size mm nor an independent set of size mm. In the proof we use the polynomial subspace method and some character theory of the complete symmmetric group.

Keywords

Cite

@article{arxiv.1412.2504,
  title  = {An explicit Ramsey graph},
  author = {Gábor Hegedüs},
  journal= {arXiv preprint arXiv:1412.2504},
  year   = {2015}
}

Comments

This paper has been withdrawn by the author due to a crucial error in the paper

R2 v1 2026-06-22T07:23:19.864Z