English
Related papers

Related papers: Weakly exact categories and the snake lemma

200 papers

Based on a Whitehead-type characterization of the sectional category we develop the notion of weak sectional category. This is a new lower bound of the sectional category, which is inspired by the notion of weak category in the sense of…

Algebraic Topology · Mathematics 2014-02-26 J. M. G. Calcines , L. Vandembroucq

A multicategory is what remains of a monoidal category when monoidal product is not available. A weak multicategory means that hom-sets are in fact categories, and in place of usual equations, there are natural isomorphisms, which have to…

Category Theory · Mathematics 2025-12-11 Volodymyr Lyubashenko

The article is developing homological algebra in modules over non-unital rings and algebras. The main application is the definition and study of (directed) homology of $(\infty,1)$-categories and of directed spaces, including relative…

Algebraic Topology · Mathematics 2026-03-13 Eric Goubault , Eliot Médioni

We give a construction of triangulated categories as quotients of exact categories where the subclass of objects sent to zero is defined by a triple of functors. This includes the cases of homotopy and stable module categories. These…

Category Theory · Mathematics 2007-08-20 Matthew Grime

We use type-theoretic techniques to present an algebraic theory of $\infty$-categories with strict units. Starting with a known type-theoretic presentation of fully weak $\infty$-categories, in which terms denote valid operations, we extend…

Logic in Computer Science · Computer Science 2022-05-27 Eric Finster , David Reutter , Alex Rice , Jamie Vicary

In this paper we redevelop the foundations of the category theory of quasi-categories (also called infinity-categories) using 2-category theory. We show that Joyal's strict 2-category of quasi-categories admits certain weak 2-limits, among…

Category Theory · Mathematics 2015-06-18 Emily Riehl , Dominic Verity

We introduce a notion of a filtered model structure and use this notion to produce various model structures on pro-categories. This framework generalizes several known examples. We give several examples, including a homotopy theory for…

Algebraic Topology · Mathematics 2007-05-23 Halvard Fausk , Daniel C. Isaksen

We investigate the extent to which the weak equivalences in a model category can be equipped with algebraic structure. We prove, for instance, that there exists a monad T such that a morphism of topological spaces admits T-algebra structure…

Category Theory · Mathematics 2022-01-31 John Bourke

We develop a theory of weak omega categories that will be accessible to anyone who is familiar with the language of categories and functors and who has encountered the definition of a strict 2-category. The most remarkable feature of this…

Category Theory · Mathematics 2007-05-23 Carl A. Futia

We consider the logic space of countable (enumerated) groups and show that closed subspaces corresponding to some standard classes of groups have (do not have) generic groups. We also discuss the cases of semigroups and associative rings.

Logic · Mathematics 2025-12-03 Aleksander Ivanov , Krzysztof Majcher

We develop a theory of descent and forms of tensor categories over arbitrary fields. We describe the general scheme of classification of such forms using algebraic and homotopical language, and give examples of explicit classification of…

Quantum Algebra · Mathematics 2012-02-07 Pavel Etingof , Shlomo Gelaki

We apply the notion of a full convex subcategory to a wide range of algebras including tilted, quasi-tilted, shod, weakly shod, left and right glued, laura, simply connected, strongly simply connected, left supported, and cluster-tilted. In…

Representation Theory · Mathematics 2020-06-30 Stephen Zito

We show that every finitely generated group admits weak analogues of an invariant expectation, whose existence characterizes exact groups. This fact has a number of applications. We show that Hopf $G$-modules are relatively injective, which…

Functional Analysis · Mathematics 2011-09-05 Ronald G. Douglas , Piotr W. Nowak

Given an algebraic theory which can be described by a (possibly symmetric) operad $P$, we propose a definition of the \emph{weakening} (or \emph{categorification}) of the theory, in which equations that hold strictly for $P$-algebras hold…

Category Theory · Mathematics 2010-02-05 M. R. Gould

We give a simple, elementary proof that a uniform algebra is weakly sequentially complete if and only if it is finite-dimensional.

Functional Analysis · Mathematics 2023-07-04 J. F. Feinstein , Alexander J. Izzo

For a collection of subcategories satisfying a fixed set of conditions, for example thick subcategories of a triangulated category, we define a topological space called classifying space of subcategories. We show that this space classifies…

Category Theory · Mathematics 2017-09-12 Yong Liu

In this paper, weakly homogeneous generalized functions in the special Colombeau algebras are determined up to equality in the sense of generalized distributions. This yields characterizations that are formally similar to distribution…

Functional Analysis · Mathematics 2014-04-01 Hans Vernaeve

The unprecedented pace of machine learning research has lead to incredible advances, but also poses hard challenges. At present, the field lacks strong theoretical underpinnings, and many important achievements stem from ad hoc design…

Machine Learning · Computer Science 2024-10-16 Francesco Riccardo Crescenzi

This thesis is devoted to the proof of a theorem showing the existence of a closed model category structure for weakly enriched categories. It requires first of all the definitions of weakly enriched categories and equivalences of weakly…

Algebraic Topology · Mathematics 2007-05-23 Regis Pellissier

We use (non-)additive sheaves to introduce an (absolute) notion of Hochschild cohomology for exact categories as Ext's in a suitable bisheaf category. We compare our approach to various definitions present in the literature.

K-Theory and Homology · Mathematics 2011-04-19 Dmitry Kaledin , Wendy Lowen