English

Geometrically Partial actions

Rings and Algebras 2019-11-25 v3

Abstract

We introduce "geometric" partial comodules over coalgebras in monoidal categories, as an alternative notion to the notion of partial action and coaction of a Hopf algebra introduced by Caenepeel and Janssen. The name is motivated by the fact that our new notion suits better if one wants to describe phenomena of partial actions in algebraic geometry. Under mild conditions, the category of geometric partial comodules is shown to be complete and cocomplete and the category of partial comodules over a Hopf algebra is lax monoidal. We develop a Hopf-Galois theory for geometric partial coactions to illustrate that our new notion might be a useful additional tool in Hopf algebra theory.

Keywords

Cite

@article{arxiv.1805.04652,
  title  = {Geometrically Partial actions},
  author = {Jiawei Hu and Joost Vercruysse},
  journal= {arXiv preprint arXiv:1805.04652},
  year   = {2019}
}

Comments

revised version; improved presentation; stronger version of "fundamental theorem" for partial comodules. Version accepted for publication in "Transactions of the American Mathematical Society". Updated references