English

Varieties of quantitative algebras as categories

Category Theory 2024-07-09 v3

Abstract

Classical varieties were characterized by Lawvere as the categories with effective congruences and a varietal generator: an abstractly finite regular generator which is regularly projective (its hom-functor preserves regular epimorphisms). We characterize varieties of quantitative algebras of Mardare, Panangaden and Plotkin analogously as metric-enriched categories. We introduce the concept of a subcongruence (a metric-enriched analogue of a congruence) and the corresponding subregular epimorphisms obtained via colimits of subcongruences. Varieties of quantitative algebras are precisely the metric-enriched categories with effective subcongruences and a subvarietal generator: an abstractly finite subregular generator which is subregularly projective (its hom-functor preserves subregular epimorphisms).

Keywords

Cite

@article{arxiv.2402.14662,
  title  = {Varieties of quantitative algebras as categories},
  author = {Jiri Adamek},
  journal= {arXiv preprint arXiv:2402.14662},
  year   = {2024}
}