On orthodox semigroups with $\Pi (L^1\times R^1)$-embeddable band of idempotents

点击翻译按钮获取中文摘要

The application at hand is a renewal of the applicant's one from June to September 2016 to June to September 2017. In an early state of preliminary work concerning this project we were led to the notion of an expansion which is an important tool for the representation of semigroups in general. Checking out whether this concept could be helpful for our considerations, we unexpectedly obtained some unifying structure theoretical results on two prominent representatives, namely the Birget-Rhodes [13] and the Margolis-Meakin group expansion [21]. Thus the project group decided to elaborate these findings first. This has meanwhile successfully been done in [9]. In particular our results provide considerably simpler proofs of some well known facts proven in [21] and [26]. Hence it seems to be reasonable to apply for a continuation of the project to tackle, among other things, the postponed original task.