English

Cross-connection structure of concordant semigroups

Group Theory 2019-01-25 v3 Category Theory

Abstract

Cross-connection theory provides the construction of a semigroup from its ideal structure using small categories. A concordant semigroup is an idempotent-connected abundant semigroup whose idempotents generate a regular subsemigroup. We characterize the categories arising from the generalised Green relations in the concordant semigroup as consistent categories and describe their interrelationship using cross-connections. Conversely, given a pair of cross-connected consistent categories, we build a concordant semigroup. We use this correspondence to prove a category equivalence between the category of concordant semigroups and the category of cross-connected consistent categories. In the process, we illustrate how our construction is a generalisation of Nambooripad's cross-connection analysis of regular semigroups. We also identify the inductive cancellative category associated with a pair of cross-connected consistent categories.

Keywords

Cite

@article{arxiv.1806.11031,
  title  = {Cross-connection structure of concordant semigroups},
  author = {P. A. Azeef Muhammed and P. G. Romeo and K. S. S. Nambooripad},
  journal= {arXiv preprint arXiv:1806.11031},
  year   = {2019}
}
R2 v1 2026-06-23T02:44:59.884Z