Ramsey monoids

Recently, Solecki [Forum Math. Sigma 7 (2019), p. 40] introduced the notion of Ramsey monoid to produce a common generalization to theorems such as Hindman’s theorem, Carlson’s theorem, and Gowers’ FINk theorem. He proved that an entire class of finite monoids is Ramsey. Here we improve this result, enlarging this class and finding a simple algebraic characterization of finite Ramsey monoids. We extend in a similar way a result of Solecki regarding a second class of monoids connected to the Furstenberg-Katznelson Ramsey theorem. The results obtained suggest a possible connection with Schützenberger’s theorem and finite automata theory.