We introduce the concept of Frobenius theory as a generalisation of Lawvere’s functorial semantics approach to categorical universal algebra. Whereas the universe for models of Lawvere theories is the category of sets and functions, or more generally cartesian categories, Frobenius theories take their models in the category of sets and relations, or more generally in cartesian bicategories.

Given a bicategory, Y , with stable local coequalizers, we construct a bicategory of monads Y -mnd by using lax functors from the generic 0-cell, 1-cell and 2-cell, respectively, into Y . Any lax functor into Y factors through Y -mnd and the 1-cells turn out to be the familiar bimodules. The locally ordered bicategory rel and its bicategory of monads both fail to be Cauchy-complete, but have a ...

To a B-coring and a (B, A)-bimodule that is finitely generated and projective as a right A-module an A-coring is associated. This new coring is termed a base ring extension of a coring by a module. We study how the properties of a bimodule such as separability and the Frobenius properties are reflected in the induced base ring extension coring. Any bimodule that is finitely generated and projec...

Interest in weak cubical n-categories arises in various contexts, in particular in topological field theories. In this paper, we describe a concept of double bicategory in terms of bicategories internal to Bicat. We show that in a special case one can reduce this to what we call a Verity double bicategory, after Domenic Verity. This is a weakened version of a double category, in the sense that ...

The context of this article is the program to develop monoidal bicategories with a feedback operation as an algebra of processes with applications to concurrency theory The objective here is to study reachability minimization and minimal realization in these bicategories In this set ting the automata are cells in contrast with previous studies where they appeared as objects As a consequence we ...

We give a formal concept of (right) wide Morita context between two 0-cells in arbitrary bicategory. We then construct a new bicategory with the same 0-cells as the oldest one, and with 1-cells all these (right) wide Morita contexts. An application to the (right) Eilenberg-Moore bicategory of comonads associated to the bimodules bicategory is also given.

We provide a description of adequate categorical data to give Turaev–Viro type state-sum construct invariants 3-manifolds with system defects, generalizing the Dijkgraaf–Witten our earlier work. term defects in construction defects-with-structure because algebraic associated them is general richer than module category over spherical fusion from which theory constructed when no defect present.

The definition and calculus of extraordinary natural transformations [EK] is extended to a context internal to any autonomous monoidal bicategory [DyS]. The original calculus is recaptured from the geometry [SV], [MT] of the monoidal bicategory V-Mod whose objects are categories enriched in a cocomplete symmetric monoidal category V and whose morphisms are modules. Mathematics Subject Classific...