Recent Advances in Algorithmic Problems for Semigroups

Abstract

In this article we survey recent progress in the algorithmic theory of matrix semigroups. The main objective in this area of study is to construct algorithms that decide various properties of finitely generated subsemi-groups of an infinite group G , often represented as a matrix group. Such problems might not be decidable in general. In fact, they gave rise to some of the earliest undecidability results in algorithmic theory. However, the situation changes when the group G satisfies additional constraints. In this survey, we give an overview of the decidability and the complexity of several algorithmic problems in the cases where G is a low-dimensional matrix group, or a group with additional structures such as commutativity, nilpotency and solvability.