English

Common idempotents in compact left topological left semirings

General Topology 2010-02-09 v1 Logic

Abstract

A classical result of topological algebra states that any compact left topological semigroup has an idempotent. We refine this by showing that any compact left topological left semiring has a common, i.e. additive and multiplicative simultaneously, idempotent. As an application, we partially answer a question related to algebraic properties of ultrafilters over natural numbers. Finally, we observe that similar arguments establish the existence of common idempotents in much more general, non-associative universal algebras.

Keywords

Cite

@article{arxiv.1002.1599,
  title  = {Common idempotents in compact left topological left semirings},
  author = {Denis I. Saveliev},
  journal= {arXiv preprint arXiv:1002.1599},
  year   = {2010}
}

Comments

Slides of my talk at International Conference on Analysis and Applications, January 24--26, Muscat, Oman. The results were announced at seminars on general topology in Moscow State University, 2005, and UltraMath 2008, Pisa, Italy

R2 v1 2026-06-21T14:44:33.251Z