Set-theoretical solutions of simplex equations
arXiv:2206.08906
Abstract
The -simplex equation (-SE) was introduced by A. B. Zamolodchikov as a generalization of the Yang--Baxter equation, which is the -simplex equation in these terms. In the present paper we suggest some general approaches to constructing solutions of -simplex equations, describe some types of solutions, introduce an operation which under some conditions allows us to construct a solution of -SE from solution of -SE and -SE. We consider the tropicalization of rational solutions and discuss a way to generalize it. We prove that if a group is an extension of a group by a group , then we can find a solution of the -SE on from solutions of this equation on and on . Also, we find solutions of the parametric Yang-Baxter equation on with parameters in . For studying solutions of the 3-simplex equations we introduce algebraic systems with ternary operations and give examples of these systems which gives solutions of the -SE. We find all elementary verbal solutions of the -SE on free groups.
52 pages, 2 figures