On special Rees matrix semigroups over semigroups

TL;DR

This paper investigates special Rees matrix semigroups over semigroups, describing their kernels, embedding properties, and constructing right commutative right cancellative semigroups, with a focus on algebraic structure and congruences.

Contribution

It introduces a detailed analysis of Rees matrix semigroups with specific sandwich matrices and establishes new embedding theorems and constructions for related semigroups.

Findings

Kernel of the right regular representation characterized

Embedding theorems for these semigroups proved

Construction method for right commutative right cancellative semigroups

Abstract

In this paper we focus on Rees $I\times \Lambda$ matrix semigroups without zero over a semigroup $S$ with $\Lambda\times I$ sandwich matrix $P$, where $I$ is a singleton, $\Lambda$ is the factor semigroup of $S$ modulo the kernel $\theta_S$ of the right regular representation of $S$, and $P$ is a choice function on the collection of all $\theta _S$-classes of $S$. We describe the kernel of the right regular representation of this type of Rees matrix semigroups, and prove embedding theorems on them. Motivated by one of embedding theorems, we show how right commutative right cancellative semigroups can be constructed. We define the concept of a right regular sequence of semigroups, and show that every congruence on an arbitrary semigroup defines such a sequence.