On Aperiodic Relational Morphisms
On Aperiodic Relational Morphisms
复制标题
论非周期关系态射
DOI:
--
复制
发表时间:
2005
期刊:
影响因子:
--
通讯作者:
B. Steinberg
中科院分区:
文献类型:
--
作者:
B. Steinberg
Abstract
We characterize aperiodic relational morphisms as those that are injective on regular
$H$-classes. This result is applied to obtain simple proofs and generalizations of McAlister’s results on joins of
aperiodic semigroups and groups. Also, we show that if $pv H$ is a proper, non-trivial pseudovariety of groups, then [pv Aast pv Hsubsetneq (pv Aast pv G)cap ov {pv H}.] We provide coordinate-free formulations and proofs of Rhodes’s Presentation Lemma and generalizations. As an application, we give simpler proofs of Tilson’s theorem on the complexity of semigroups
with at most $2$ non-zero $J$-classes and Rhodes’s theorem that complexity is not local.