Given a bisimplicial set, there are two ways to extract from it a simplicial set: the diagonal simplicial set and the less well known total simplicial set of Artin and Mazur. There is a natural comparison map between these simplicial sets, and it is a theorem due to Cegarra and Remedios and independently Joyal and Tierney, that this comparison map is a weak homotopy equivalence for any bisimpli...

For a commutative ring k, the homotopy category of commutative Hk-algebras (strictly unital E∞ ring spectra under the Eilenberg-Mac Lane spectrum Hk) is equivalent to the homotopy category of E∞ differential graded k-algebras. The functor from topology to algebra is a CW approximation and cellular chain functor; the inverse equivalence is constructed by Brown’s representability theorem.

We generalize the main theorem of Rieffel for Morita equivalence of W -algebras to the case of unital dual operator algebras: two unital dual operator algebras A,B have completely isometric normal representations α, β such that α(A) = [Mβ(B)M] ∗ and β(B) = [Mα(A)M] ∗ for a ternary ring of operators M (i.e. a linear space M such that MMM ⊂ M) if and only if there exists an equivalence functor F ...

The (dual) Dold-Kan correspondence says that there is an equivalence of categories K : Ch → Ab between nonnegatively graded cochain complexes and cosimplicial abelian groups, which is inverse to the normalization functor. We show that the restriction of K to DG-rings can be equipped with an associative product and that the resulting functor DGR → Rings, although not itself an equivalence, does ...

We discuss the use of relation lifting in the theory of set-based coalgebra and coalgebraic logic. On the one hand we prove that the neighborhood functor does not extend to a relation lifting of which the associated notion of bisimilarity coincides with behavioral equivalence. On the other hand we argue that relation liftings may be of use for many other functors that do not preserve weak pullb...

The path category P (X) of a simplicial set X defines a functor X 7→ P (X) which is left adjoint to the nerve functor B : cat → sSet. The first section of this paper contains an elementary description of this functor, with some of its basic properties. This construction specializes to a path category functor for cubical sets which appears in the second section. The path category construction is...

Coalgebras provide a uniform framework to study dynamical systems, including several types of automata. In this paper, we make use of the coalgebraic view on systems to investigate, in a uniform way, under which conditions calculi that are sound and complete with respect to behavioral equivalence can be extended to a coarser coalgebraic language equivalence, which arises from a generalised powe...

Artin glueings of frames correspond to adjoint split extensions in the category and finite-meet-preserving maps. We extend these ideas setting toposes show that a 2-categorical notion 2-category toposes, finite-limit-preserving functors natural transformations. A morphism between is introduced, which allows Ext(H,N) be constructed. contravariantly equivalent Hom(H,N), moreover, this can extende...

In this work, using the functoriality of Drinfeld center fusion categories, we generalize full simple separable algebras in a fixed category to all categories. This generalization produces new functor, which involves both and is called pointed functor. We prove that functor symmetric monoidal equivalence. It turns out provides precise rather complete mathematical formulation boundary-bulk relat...

We provide a more economical refined version of Evrard’s categorical cocylinder factorization of a functor [Ev1,2]. We show that any functor between small categories can be factored into a homotopy equivalence followed by a (co)fibred functor which satisfies the (dual) assumption of Quillen’s Theorem B. Introduction The problem treated here is how to replace a functor f : C→ D between small cat...