We explain the sense in which a warping on a monoidal category is the same as
a pseudomonad on the corresponding one-object bicategory, and we describe
extensions of this to the setting of skew monoidal categories: these are a
generalization of monoidal categories in which the associativity and unit maps
are not required to be invertible. Our analysis leads us to describe a
normalization process for skew monoidal categories, which produces a universal
skew monoidal category for which the right unit map is invertible.Comment: 15 pages. Version 2: revised based on a very helpful report from the
referee. To appear in the Cahiers de Topologie and Geometrie Differentielle
Categorique