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Related papers: Brown representability for space-valued functors

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We give a description of simple functors taking finitely generated values, from a small additive category to the category of vector spaces over a field. This result is analogous to Steinberg's tensor product theorems in group representation…

Representation Theory · Mathematics 2021-05-05 Aurélien Djament , Antoine Touzé , Christine Vespa

Given a functor $\varphi : \mathcal{C} \to \mathcal{D}$ between two small categories, there is a homotopy equivalence $\kappa: hocolim _{\mathcal{D}} N(\varphi /-) \to N\mathcal{C}$ where $N(\varphi/-)$ is the functor which sends every…

Algebraic Topology · Mathematics 2026-04-02 Mehmet Kirtisoglu , Ergun Yalcin

We give a characterisation of functors whose induced functor on the level of localisations is an equivalence and where the isomorphism inverse is induced by some kind of replacements such as projective resolutions or cofibrant replacements.

Category Theory · Mathematics 2018-10-11 Sebastian Thomas

We solve two problems in the theory of correspondences that have important implications in the theory of product systems. The first problem is the question whether every correspondence is the correspondence associated (by the representation…

Operator Algebras · Mathematics 2013-11-20 M. Skeide

It is known that pure row contractions with one-dimensional defect spaces can be classified up to unitary equivalence by compressions of the standard $d$-shift acting on the full Fock space. Upon settling for a softer relation than unitary…

Functional Analysis · Mathematics 2018-09-10 Raphaël Clouâtre , Edward J. Timko

Given any pointed CW complex (X,x), it is well known that the fondamental group of X pointed at x is naturally isomorphic to the automorphism group of the functor which associates to a locally constant sheaf on X its fibre at x. The purpose…

Algebraic Topology · Mathematics 2007-05-23 B. Toen

Given a fixed tensor triangulated category S we consider triangulated categories T together with an S-enrichment which is compatible with the triangulated structure of T. It is shown that, in this setting, an enriched analogue of Brown…

Category Theory · Mathematics 2016-04-05 Johan Steen , Greg Stevenson

In this paper, we prove the integrality conjecture for quotient stacks arising from weakly symmetric representations of reductive groups. Our main result is a decomposition of the cohomology of the stack into finite-dimensional components…

Representation Theory · Mathematics 2026-01-21 Lucien Hennecart

We compare the bicategory of spans with that of bisets (a.k.a. bimodules, distributors, profunctors) in the context of finite groupoids. We construct in particular a well-behaved pseudo-functor from spans to bisets. This yields an…

Category Theory · Mathematics 2020-09-10 Ivo Dell'Ambrogio , James Huglo

We introduce the notion of weak containment for stationary actions of a countable group and define a natural topology on the space of weak equivalence classes. We prove that Furstenberg entropy is an invariant of weak equivalence, and…

Dynamical Systems · Mathematics 2016-11-04 Peter Burton , Martino Lupini , Omer Tamuz

We introduce and study a notion of cylinder coherator similar to the notion of Grothendieck coherator which define more flexible notion of weak infinity groupoids. We show that each such cylinder coherator produces a combinatorial…

Category Theory · Mathematics 2016-09-16 Simon Henry

The normalized singular chains of a path connected pointed space $X$ may be considered as a connected $E_{\infty}$-coalgebra $\mathbf{C}_*(X)$ with the property that the $0^{\text{th}}$ homology of its cobar construction, which is naturally…

Algebraic Topology · Mathematics 2019-01-24 Manuel Rivera , Felix Wierstra , Mahmoud Zeinalian

We classify irreducible representations of the special linear groups in positive characteristic with small weight multiplicities with respect to the group rank and give estimates for the maximal weight multiplicities. For the natural…

Representation Theory · Mathematics 2013-10-01 Alexander Baranov , Anna Osinovskaya , Irina Suprunenko

It is a deep fact that the homotopy classification of topological manifolds is convariantly functorial. In other words, a map from a topological manifold M to another N naturally induces a map from the structure set S(M) to S(N). We extend…

Geometric Topology · Mathematics 2009-09-29 Sylvain Cappell , Shmuel Weinberger , Min Yan

We investigate functorial properties of Putnam's homology theory for Smale spaces. Our analysis shows that the addition of a conjugacy condition is necessary to ensure functoriality. Several examples are discussed that elucidate the need…

Dynamical Systems · Mathematics 2019-02-20 Robin J. Deeley , D. Brady Killough , Michael F. Whittaker

We construct a Goodwillie tower of categories which interpolates between the category of pointed spaces and the category of spectra. This tower of categories refines the Goodwillie tower of the identity functor in a precise sense. More…

Algebraic Topology · Mathematics 2018-07-26 Gijs Heuts

Everyone knows that if you have a bivariant homology theory satisfying a base change formula, you get an representation of a category of correspondences. For theories in which the covariant and contravariant transfer maps are in mutual…

Category Theory · Mathematics 2022-12-21 Andrew W. Macpherson

We compute the equivariant cohomology of complex projective spaces associated to finite-dimensional representations of $C_2$, using ordinary cohomology graded on representations of the fundamental groupoid, with coefficients in the Burnside…

Algebraic Topology · Mathematics 2022-05-17 Steven R. Costenoble , Thomas Hudson , Sean Tilson

The Brown Representability Theorem implies that cohomology operations can be represented by continuous maps between Eilenberg-Maclane spaces. These Eilenberg-Maclane spaces have explicit geometric models as spaces of cycles on round spheres…

Algebraic Topology · Mathematics 2025-10-15 Herng Yi Cheng

This paper is a contribution to the development of the theory of representations of inverse semigroups in toposes. It continues the work initiated by Funk and Hofstra. For the topos of sets, we show that torsion-free functors on…

Rings and Algebras · Mathematics 2024-11-12 Ganna Kudryavtseva , Primož Škraba