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Related papers: Accessibility and presentability in 2-categories

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In this paper we study compact closed categories within the context of homotopical algebra. We construct two new model category structures by localizing two (Quillen equivalent) model categories of symmetric monoidal categories with the…

Category Theory · Mathematics 2021-02-26 Amit Sharma

This paper introduces the notion of weakly globular double categories, a particular class of strict double categories, as a way to model weak 2-categories; it explores its use in defining a double category of fractions, and shows that the…

Category Theory · Mathematics 2013-03-28 Simona Paoli , Dorette Pronk

The bicategorical point of view provides a natural setting for many concepts in the representation theory of monoidal categories. We show that centers of twisted bimodule categories correspond to categories of 2-dimensional natural…

Category Theory · Mathematics 2023-06-09 Bojana Femić , Sebastian Halbig

We generalise the notion of separable equivalence, originally presented by Linckelmann (2011), to an equivalence relation on additive categories. We use this generalisation to show that from an initial equivalence between two algebras we…

Representation Theory · Mathematics 2017-11-01 Simon F Peacock

A topological group $G$ is called extremely amenable if every continuous action of $G$ on a compact space has a fixed point. This concept is linked with geometry of high dimensions (concentration of measure). We show that a von Neumann…

Operator Algebras · Mathematics 2007-09-03 Thierry Giordano , Vladimir Pestov

Recall that the definition of the $K$-theory of an object C (e.g., a ring or a space) has the following pattern. One first associates to the object C a category A_C that has a suitable structure (exact, Waldhausen, symmetric monoidal, ...).…

K-Theory and Homology · Mathematics 2011-11-15 Nicolas Michel

We motivate and give semantics to theory presentation combinators as the foundational building blocks for a scalable library of theories. The key observation is that the category of contexts and fibered categories are the ideal theoretical…

Mathematical Software · Computer Science 2014-02-25 Jacques Carette , Russell O'Connor

In this paper we study obstructions to presentability by products for finitely generated groups. Along the way we develop both the concept of acentral subgroups, and the relations between presentability by products on the one hand, and…

Group Theory · Mathematics 2013-02-11 D. Kotschick , C. Loeh

Optics and lenses are abstract categorical gadgets that model systems with bidirectional data flow. In this paper we observe that the denotational definition of optics - identifying two optics as equivalent by observing their behaviour from…

Category Theory · Mathematics 2022-09-21 Bruno Gavranović

This paper studies the combinatorics of ideals which recently appeared in ergodicity results for analytic equivalence relations. The ideals have the following topological representation. There is a separable metrizable space $X$, a…

Logic · Mathematics 2013-03-06 Adam Kwela , Marcin Sabok

This is an expository account of the following result: we can construct a group by means of twisted Z_2-graded vectorial bundles which is isomorphic to K-theory twisted by any degree three integral cohomology class.

K-Theory and Homology · Mathematics 2008-03-08 Kiyonori Gomi

We exhibit an extension of the category of class two nilpotent groups. It has the same objects but, unlike the latter, its morphisms are closed under pointwise addition of maps. At the same time the class of its morphisms is much smaller…

Group Theory · Mathematics 2007-05-23 Mamuka Jibladze , Teimuraz Pirashvili

Motivated by some problems proposed by Cuadra and Simson related to flat objects in finitely accessible Grothendieck categories, we study flatness in the more general setting of finitely accessible additive categories. For such category…

Category Theory · Mathematics 2025-05-13 Manuel Cortés-Izurdiaga

Skew-gentle algebras are skew-group algebras of certain gentle algebras endowed with a Z 2-action. Using the topological description of Opper, Plamondon and Schroll in [OPS] for the indecomposable objects of the derived category of any…

Representation Theory · Mathematics 2022-01-19 Claire Amiot

We show that every combinatorial model category can be obtained, up to Quillen equivalence, by localizing a model category of diagrams of simplicial sets. This says that any combinatorial model category can be built up from a category of…

Algebraic Topology · Mathematics 2007-05-23 Daniel Dugger

For a semisimple multiring category with left duals, we prove that the unit object is simple if and only if the tensor functors by any non-zero algebra are separable (resp. faithful, resp. Maschke, resp. dual Maschke, resp. conservative).…

Category Theory · Mathematics 2026-02-10 Zhenbang Zuo

In this paper we prove an $\infty$-categorical version of the reflection theorem of Ad\'amek-Rosick\'y. Namely, that a full subcategory of a presentable $\infty$-category which is closed under limits and $\kappa$-filtered colimits is a…

Algebraic Topology · Mathematics 2022-07-20 Shaul Ragimov , Tomer M. Schlank

Employing a formal analogy between ordered sets and topological spaces, over the past years we have investigated a notion of cocompleteness for topological, approach and other kind of spaces. In this new context, the down-set monad becomes…

Category Theory · Mathematics 2013-05-28 Dirk Hofmann

We investigate the classical aspects of Quantum theory and under which description Quantum theory does appear Classical. Although such descriptions or variables are known as "ontological" or "hidden", they are not hidden at all, but are…

Quantum Physics · Physics 2025-01-22 Diego J. Cirilo-Lombardo , Norma G. Sanchez

This paper provides an extensive study of the homotopy theory of types of algebras with units, like unital associative algebras or unital commutative algebras for instance. To this purpose, we endow the Koszul dual category of curved…

Algebraic Topology · Mathematics 2019-05-29 Brice Le Grignou