English
Related papers

Related papers: A Theorem of Van Kampen Type for Pseudo Peano Cont…

200 papers

We construct an exact tensor functor from the category $\mathcal{A}$ of finite-dimensional graded modules over the quiver Hecke algebra of type $A_\infty$ to the category $\mathscr C_{B^{(1)}_n}$ of finite-dimensional integrable modules…

Representation Theory · Mathematics 2017-10-19 Masaki Kashiwara , Myungho Kim , Se-jin Oh

Results on the finiteness of induced crossed modules are proved both algebraically and topologically. Using the Van Kampen type theorem for the fundamental crossed module, applications are given to the 2-types of mapping cones of…

Group Theory · Mathematics 2009-09-25 Ronald Brown , Christopher D. Wensley

For an exact dg category $\mathcal A$, we introduce its bounded dg derived category $\mathcal{D}^b_{dg}(\mathcal A)$ and establish the universal exact morphism from $\mathcal A$ to $\mathcal{D}^b_{dg}(\mathcal A)$. We prove that the dg…

Representation Theory · Mathematics 2024-06-18 Xiaofa Chen

We initiate the study of derived functors in the setting of extriangulated categories. By using coends, we adapt Yoneda's theory of higher extensions to this framework. We show that, when there are enough projectives or enough injectives,…

Category Theory · Mathematics 2021-03-24 Mikhail Gorsky , Hiroyuki Nakaoka , Yann Palu

Adhesive categories are categories which have pushouts with one leg a monomorphism, all pullbacks, and certain exactness conditions relating these pushouts and pullbacks. We give a new proof of the fact that every topos is adhesive. We also…

Category Theory · Mathematics 2011-04-14 Stephen Lack

We survey the existing parts of a classification of finite groups generated by orthogonal transformations in a finite-dimensional Euclidean space whose fixed point subspace has codimension one or two and extend it to a complete…

Group Theory · Mathematics 2017-11-02 Christian Lange , Marina A. Mikhailova

We compute the presentations of fundamental groups of the complements of a class of rational cuspidal projective plane curves classified by Flenner, Zaidenberg, Fenske and Saito. We use the Zariski-Van Kampen algorithm and exploit the…

Algebraic Geometry · Mathematics 2015-09-15 A. Muhammed Uludağ

We generalise recent results of M. Hovey and N. Strickland on comodule categories for Landweber exact algebras using the formalism of algebraic stacks.

Algebraic Topology · Mathematics 2007-05-23 Niko Naumann

We consider an intermediate category between the category of finite quivers and a certain category of pseudocompact associative algebras whose objects include all pointed finite dimensional algebras. We define the completed path algebra and…

Rings and Algebras · Mathematics 2017-08-04 Kostiantyn Iusenko , John MacQuarrie

We introduce and study relatively divisible and relatively flat objects in exact categories in the sense of Quillen. For every relative cotorsion pair $(\mathcal{A},\mathcal{B})$ in an exact category $\mathcal{C}$, $\mathcal{A}$ coincides…

Category Theory · Mathematics 2018-10-30 Septimiu Crivei , Derya Keskin Tütüncü

This paper is the first part of a series that investigates the existence of $n$-exact structures on idempotent complete additive categories for positive integers $n$. It is shown that every idempotent complete additive category has a unique…

Category Theory · Mathematics 2024-10-08 Carlo Klapproth

We introduce and study a Serre functor in the category ${\cal P}_d$ of strict polynomial functors over a field of positive characteristic. By using it we obtain the Poincar\'e duality formula for Ext--groups from [C3] in elementary way. We…

K-Theory and Homology · Mathematics 2016-03-22 Marcin Chałupnik

In this paper, we solve a classical counting problem for non-degenerate quadratic forms defined on a vector space in odd characteristic; given a subspace $\pi$, we determine the number of non-singular subspaces that are trivially…

Combinatorics · Mathematics 2024-09-20 Maarten De Boeck , Geertrui Van de Voorde

Using the topologist sine curve we present a new functorial construction of cone-like spaces, starting in the category of all path-connected topological spaces with a base point and continuous maps, and ending in the subcategory of all…

Geometric Topology · Mathematics 2008-03-29 Katsuya Eda , Umed H. Karimov , Dušan Repovš

The author has shown that the category of analytic contravariant functors on $\mathbf{gr}$, the category of finitely-generated free groups, is equivalent to the category of left modules over the PROP associated to the Lie operad, working…

Algebraic Topology · Mathematics 2023-09-15 Geoffrey Powell

Several important types of categories have been shown to be both exact and coexact (in the sense of Barr). The first type consists of abelian categories, which due to their self-dual definition, can be seen to be both exact and coexact by…

Category Theory · Mathematics 2026-03-30 James Richard Andrew Gray

Various models of $(\infty,1)$-categories, including quasi-categories, complete Segal spaces, Segal categories, and naturally marked simplicial sets can be considered as the objects of an $\infty$-cosmos. In a generic $\infty$-cosmos, whose…

Category Theory · Mathematics 2017-02-08 Emily Riehl , Dominic Verity

We construct a symmetric monoidal closed category of polynomial endofunctors (as objects) and simulation cells (as morphisms). This structure is defined using universal properties without reference to representing polynomial diagrams and is…

Logic in Computer Science · Computer Science 2015-07-01 Hyvernat Pierre

Notions and techniques of enriched category theory can be used to study topological structures, like metric spaces, topological spaces and approach spaces, in the context of topological theories. Recently in [D. Hofmann, Injective spaces…

Category Theory · Mathematics 2008-07-28 Maria Manuel Clementino , Dirk Hofmann

We have defined almost separable space. We show that like separability, almost separability is $c$ productive and converse also true under some restrictions. We establish a Baire Category theorem like result in Hausdorff, Pseudocompacts…

General Topology · Mathematics 2020-02-13 Sagarmoy Bag , Ram Chandra Manna , Sourav Kanti Patra