Constructive lower bounds on classical multicolor Ramsey numbers
Summary: This paper studies lower bounds for classical multicolor Ramsey numbers, first by giving a short overview of past results, and then by presenting several general constructions establishing new lower bounds for many diagonal and off-diagonal multicolor Ramsey numbers. In particular, we improve several lower bounds for \(R_k(4)\) and \(R_k(5)\) for some small \(k\), including \(415\leq R_3(5)\), \(634\leq R_4(4)\), \(2721\leq R_4(5)\), \(3416\leq R_5(4)\) and \(26082\leq R_5(5)\). Most of the new lower bounds are consequences of general constructions.
scientific article; zbMATH DE number 2107477