English

Colimit-Dense Subcategories

Category Theory 2020-12-04 v1

Abstract

Among cocomplete categories, the locally presentable ones can be defined as those with a strong generator consisting of presentable objects. Assuming Vop{\v{e}}nka's Principle, we prove that a cocomplete category is locally presentable iff it has a colimit dense subcategory and a generator consisting of presentable objects. We further show that a 33-element set is colimit-dense in \Set^{\op}, and spaces of countable dimension are colimit-dense in \Vecop\Vec^{op}.

Keywords

Cite

@article{arxiv.1812.10649,
  title  = {Colimit-Dense Subcategories},
  author = {J. Adámek and A. Brooke-Taylor and T. Campion and L. Positselski and J. Rosický},
  journal= {arXiv preprint arXiv:1812.10649},
  year   = {2020}
}
R2 v1 2026-06-23T06:57:06.230Z