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Related papers: On continuity of accessible functors

200 papers

A graph $\Gamma$ is $k$-connected-homogeneous ($k$-CH) if $k$ is a positive integer and any isomorphism between connected induced subgraphs of order at most $k$ extends to an automorphism of $\Gamma$, and connected-homogeneous (CH) if this…

Group Theory · Mathematics 2020-03-10 Alice Devillers , Joanna B. Fawcett , Cheryl E. Praeger , Jin-Xin Zhou

Adjoint functor theorems give necessary and sufficient conditions for a functor to admit an adjoint. In this paper we prove general adjoint functor theorems for functors between $\infty$-categories. One of our main results is an…

Category Theory · Mathematics 2019-09-18 Hoang Kim Nguyen , George Raptis , Christoph Schrade

A function $f:X\to Y$ between topological spaces is called {\em compact-preserving} if the image $f(K)$ of each compact subset $K\subset X$ is compact. We prove that a function $f:X\to Y$ defined on a strong Frechet space $X$ is…

General Topology · Mathematics 2013-05-28 Taras Banakh , Artur Bartoszewicz , Marek Bienias , Szymon Glab

We give conditions on a finitary endofunctor of a finitely accessible category to admit a final coalgebra. Our conditions always apply to the case of a finitary endofunctor of a locally finitely presentable (l.f.p.) category and they bring…

Category Theory · Mathematics 2009-06-01 Panagis Karazeris , Apostolos Matzaris , Jiri Velebil

It is shown that every concretizable category can be fully embedded into the category of accessible set functors and natural transformations.

Category Theory · Mathematics 2019-09-12 Libor Barto

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

Category Theory · Mathematics 2020-12-04 Jiri Rosicky , Walter Tholen

We show that Klemenc's stable envelope of exact $\infty$-categories induces an equivalence between stable $\infty$-categories with a bounded heart structure and weakly idempotent complete exact $\infty$-categories. Moreover, we generalise…

K-Theory and Homology · Mathematics 2025-12-01 Victor Saunier , Christoph Winges

A map $f:X\to Y$ between topological spaces is skeletal if the preimage $f^{-1}(A)$ of each nowhere dense subset $A\subset Y$ is nowhere dense in $X$. We prove that a normal functor $F:Comp\to Comp$ is skeletal (which means that $F$…

General Topology · Mathematics 2012-12-19 Taras Banakh , Andrzej Kucharski , Marta Martynenko

If there is a topologically locally constant family of smooth algebraic varieties together with an admissible normal function on the total space, then the latter is constant on any fiber if this holds on some fiber. Combined with spreading…

Algebraic Geometry · Mathematics 2014-11-25 Morihiko Saito

Given a Woodin cardinal $\delta$, I show that if $F$ is any Easton function with $F"\delta\subseteq\delta$ and $\GCH$ holds, then there is a cofinality-preserving forcing extension in which $2^\gamma= F(\gamma)$ for each regular cardinal…

Logic · Mathematics 2012-09-07 Brent Cody

We extend Bourke and Garner's idempotent adjunction between monads and pretheories to the framework of $\infty$-categories and we use this to prove many classical results about monads in the $\infty$-categorical framework. Amongst other…

Category Theory · Mathematics 2021-06-17 Simon Henry , Nicholas J. Meadows

The article investigates the question of under what conditions a functor between small categories preserves cohomology groups when passing to the inverse image. For example, it is known that the left adjoint functor preserves the category…

Category Theory · Mathematics 2023-06-29 Ahmet A. Husainov

Let $\Gamma$ be a Polish space and let $K$ be a separable and pointwise compact set of real-valued functions on $\Gamma$. It is shown that if each function in $K$ has only countably many discontinuities then $C(K)$ may be equipped with a…

Functional Analysis · Mathematics 2007-05-23 R Haydon , A Molto , J Orihuela

A Quillen model structure is presented by an interacting pair of weak factorization systems. We prove that in the world of locally presentable categories, any weak factorization system with accessible functorial factorizations can be lifted…

Category Theory · Mathematics 2022-05-23 Richard Garner , Magdalena Kedziorek , Emily Riehl

Suppose $f(x,y) + \frac{\kappa}{2} \|x\|^2 - \frac{\sigma}{2}\|y\|^2$ is convex where $\sigma>0$, and the argmin function $\gamma(x) = \{ \gamma : \inf_y f(x,y) = f(x,\gamma)\}$ exists and is single valued. We will prove $\gamma$ is…

Analysis of PDEs · Mathematics 2019-05-31 Julius Ross , David Witt Nyström

We systematically develop the theory of definable functors between compactly generated triangulated categories. Such functors preserve pure triangles, pure injective objects, and definable subcategories, and as such appear in a wide range…

Category Theory · Mathematics 2025-03-03 Isaac Bird , Jordan Williamson

We show relative to strong hypotheses that patterns of compact cardinals in the universe, where a compact cardinal is one which is either strongly compact or supercompact, can be virtually arbitrary. Specifically, we prove if V is a model…

Logic · Mathematics 2007-05-23 Arthur W. Apter

We investigate categoricity of abstract elementary classes without any remnants of compactness (like non-definability of well ordering, existence of E.M. models or existence of large cardinals). We prove (assuming a weak version of GCH…

Logic · Mathematics 2016-09-07 Saharon Shelah

For a countable group $G$ we construct a small, idempotent complete, symmetric monoidal, stable $\infty$-category $\mathrm{KK}^{G}_{\mathrm{sep}}$ whose homotopy category recovers the triangulated equivariant Kasparov category of separable…

Operator Algebras · Mathematics 2025-12-03 Ulrich Bunke , Alexander Engel , Markus Land

Suppose $\kappa$ is $\lambda$-supercompact witnessed by an elementary embedding $j:V\rightarrow M$ with critical point $\kappa$, and further suppose that $F$ is a function from the class of regular cardinals to the class of cardinals…

Logic · Mathematics 2013-11-05 Brent Cody , Sy-David Friedman , Radek Honzik