Monoidal categories and multiextensions
Abstract
Description
We show that the obstruction to the existence of a strict symmetric monoidal structure on a monoidal stack $\cal C$ is determined by a commutator biextension associated to $\cal C$, and that this biextension is alternating under an additional hypothesis. The analogous construction for monoidal 2-stacks is described, together with the corresponding generalizations of the concept of a biextension.
LaTeX, xy-pic, 38 pages
LaTeX, xy-pic, 38 pages