Skew monoidales, skew warpings and quantum categories
Abstract
Kornel Szlachányi recently used the term skew-monoidal category for a particular laxified version of monoidal category. He showed that bialgebroids $H$ with base ring $R$ could be characterized in terms of skew-monoidal structures on the category of one-sided $R$-modules for which the lax unit was $R$ itself. We define skew monoidales (or skew pseudo-monoids) in any monoidal bicategory $\mathscr M$. These are skew-monoidal categories when $\mathscr M$ is $\mathrm{Cat}$. Our main results are presented at the level of monoidal bicategories. However, a consequence is that quantum categories in the sense of Day-Street with base comonoid $C$ in a suitably complete braided monoidal category $\mathscr V$ are precisely skew monoidales in $\mathrm{Comod} (\mathscr V)$ with unit coming from the counit of $C$. Quantum groupoids are those skew monoidales with invertible associativity constraint. In fact, we provide some very general results connecting opmonoidal monads and skew monoidales. We use a lax version of the concept of warping defined recently by Booker-Street to modify monoidal structures.
- Publication:
-
arXiv e-prints
- Pub Date:
- April 2012
- DOI:
- 10.48550/arXiv.1205.0074
- arXiv:
- arXiv:1205.0074
- Bibcode:
- 2012arXiv1205.0074L
- Keywords:
-
- Mathematics - Category Theory;
- Mathematics - Quantum Algebra
- E-Print:
- Minor changes and some renumbering in this version