activity
20022025
most citedNotions of Lawvere theory

51 citations · 273 across the 33 of their papers we have counts for

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27 papers · 1 filter

math.CT2021

Varieties of ordered algebras as categories

Jiří Adámek, Jiří Rosický

A variety is a category of ordered (finitary) algebras presented by inequations between terms. We characterize categories enriched over the category of posets which are equivalent…

math.CT2020

Metric monads

JIří Rosický

We develop universal algebra over an enriched category and relate it to finitary enriched monads over . Using it, we deduce recent results about ordered un…

math.CT2020

Are Banach spaces monadic?

Jiří Rosický

We will show that Banach spaces are monadic over complete metric spaces via the unit ball functor. For the forgetful functor, one should take complete pointed metric spaces.

math.CT2020

Minimal accessible categories

Jiří Rosický

We give a purely category-theoretic proof of the result of Makkai and Paré saying that the category of linearly ordered sets and order preserving injective mappings is a…

math.CT2020

Approximate injectivity and smallness in metric-enriched categories

Jiří Adámek, Jiří Rosický

Properties of categories enriched over the category of metric spaces are investigated and applied to a study of constructions known from that category and the category of Banach sp…

math.CT2020

Cofibrant generation of pure monomorphisms

Michael Lieberman, Leonid Positselski, Jiri Rosicky +1

We show that pure monomorphisms are cofibrantly generated---generated from a set of morphisms by pushouts, transfinite composition, and retracts---in any locally finitely presentab…

math.CT2019★ 2 cited

Hilbert spaces and -algebras are not finitely concrete

Michael Lieberman, Jiří Rosický, Sebastien Vasey

We show that no faithful functor from the category of Hilbert spaces with linear isometries into the category of sets preserves directed colimits. Thus Hilbert spaces cannot form a…

math.CT2019

Cellular categories and stable independence

Michael Lieberman, Jiří Rosický, Sebastien Vasey

We exhibit a bridge between the theory of cellular categories, used in algebraic topology and homological algebra, and the model-theoretic notion of stable independence. Roughly sp…

math.CT2017★ 4 cited

Nearly locally presentable categories

Leonid Positselski, Jiri Rosicky

We introduce a new class of categories generalizing locally presentable ones. The distinction does not manifest in the abelian case and, assuming Vopenka's principle, the same happ…

math.CT2017

On the uniqueness of cellular injectives

Jiří Rosický

A. Avilés and C. Brech proved a intriguing result about the existence and uniqueness of certain injective Boolean algebras or Banach spaces. Their result refines the standard exist…

math.CT2016

Approximate injectivity

Jiri Rosicky, Walter Tholen

In a locally -presentable category, with a regular cardinal, classes of objects that are injective with respect to a family of morphisms whose domains and codomains are -…

math.CT2016

Elementary equivalences and accessible functors

Tibor Beke, Jiri Rosicky

We introduce the notion of -equivalence and -embeddings of objects in suitable categories. This notion specializes to -equivalence and -elementary e…

math.CT2015★ 41 cited

Covers, envelopes, and cotorsion theories in locally presentable abelian categories and contramodule categories

Leonid Positselski, Jiri Rosicky

We prove general results about completeness of cotorsion theories and existence of covers and envelopes in locally presentable abelian categories, extending the well-established th…

math.CT2015★ 3 cited

On reflective subcategories of locally presentable categories

Jiri Adamek, Jiri Rosicky

Are all subcategories of locally finitely presentable categories that are closed under limits and -filtered colimits also locally presentable? For full subcategories the answer…

math.CT2015★ 1 cited

Accessible model categories

J. Rosicky

We prove that a weak factorization system on a locally presentable category is accessible if and only if it is small generated in the sense of R. Garner. Moreover, we discuss an an…

math.CT2014

Cellular objects and Shelah's singular compactness theorem

Tibor Beke, Jiri Rosicky

The best-known version of Shelah's celebrated singular cardinal compactness theorem states that if the cardinality of an abelian group is singular, and all its subgroups of lesser…

math.CT2013★ 1 cited

Homotopy locally presentable enriched categories

Stephen Lack, Jiri Rosicky

We develop a homotopy theory of categories enriched in a monoidal model category V. In particular, we deal with homotopy weighted limits and colimits, and homotopy local presentabi…

math.CT2012

Rigidification of algebras over essentially algebraic theories

J. Rosicky

Badzioch and Bergner proved a rigidification theorem saying that each homotopy simplicial algebra is weakly equivalent to a simplicial algebra. The question is whether this result…

math.CT2011

Colimits of accessible categories

R. Pare, J. Rosicky

We show that any directed colimit of acessible categories and accessible full embeddings is accessible and, assuming the existence of arbitrarily large strongly compact cardinals,…

math.CT2011★ 25 cited

Locally class-presentable and class-accessible categories

Boris Chorny, Jiri Rosicky

We generalize the concepts of locally presentable and accessible categories. Our framework includes such categories as small presheaves over large categories and ind-categories. Th…

math.CT2011

Definable orthogonality classes in accessible categories are small

Joan Bagaria, Carles Casacuberta, A. R. D. Mathias +1

We lower substantially the strength of the assumptions needed for the validity of certain results in category theory and homotopy theory which were known to follow from Vopenka's p…

math.CT2010★ 15 cited

Enriched weakness

Stephen Lack, Jiri Rosicky

The basic notions of category theory, such as limit, adjunction, and orthogonality, all involve assertions of the existence and uniqueness of certain arrows. Weak notions arise whe…

math.CT2010★ 2 cited

Abstract elementary classes and accessible categories

Tibor Beke, Jiri Rosicky

We compare abstract elementary classes of Shelah with accessible categories having directed colimits.

math.CT2009★ 3 cited

Are all cofibrantly generated model categories combinatorial?

J. Rosicky

G. Raptis has recently proved that, assuming Vopěnka's principle, every cofibrantly generated model category is Quillen equivalent to a combinatorial one. His result remains true f…