Monoidal objects (or pseudomonoids) in monoidal bicategories share many of the properties of the paradigmatic example: monoidal categories. The existence of (say, left) duals in a monoidal category leads to a dualization operation which was abstracted to the context of monoidal objects by Day et al. (Appl Categ Struct 11:229-260, 2003). We define a relative version of this called exact pairing for two arrows in a monoidal bicategory; when one of the arrows is an identity, the other is a dualization. In this context we supplement results of Day et al. (Appl Categ Struct 11:229-260, 2003) (and even correct one of them) and only assume the existence of biduals in the bicategory where necessary. We also abstract recent work of Day and Pastro (New York J Math 14:733-742, 2008) on Frobenius monoidal functors to the monoidal bicategory context. Our work began by focusing on the invertibility of The first author was supported by an Internal Graduate Studentship at Trinity College, Cambridge, and by the Fondation Sciences Mathématiques de Paris.The second and third authors gratefully acknowledge financial support from the Australian ARC and the Canadian NSERC. Diagrams typeset using M. Barr's diagram package, diagxy.tex. I. López Franco et al. components at dual objects of monoidal natural transformations between Frobenius monoidal functors. As an application of the abstraction, we recover a theorem of Walters and Wood (Theory Appl Categ 3:25-47, 2008) asserting that, for objects A and X in a cartesian bicategory C , if A is Frobenius then the category MapC (X, A) of left adjoint arrows is a groupoid. Also, the characterization in Walters and Wood (Theory Appl Categ 3:25-47, 2008) of left adjoint arrows between Frobenius objects of a cartesian bicategory is put into our current setting. In the same spirit, we show that when a monoidal object admits a dualization, its lax centre coincides with the centre defined in Street (Theory Appl Categ 13:184-190, 2004). Finally we look at the relationship between lax duals for objects and adjoints for arrows in a monoidal bicategory.
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