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Related papers: Functors from Association Schemes

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In a recent paper [3], the authors introduced a map $\mathcal{F}$ which associates a Deitmar scheme (which is defined over the field with one element, denoted by $\mathbb{F}_1$) with any given graph $\Gamma$. By base extension, a scheme…

Algebraic Geometry · Mathematics 2016-05-10 Manuel Merida-Angulo , Koen Thas

In this survey, we summarize some results in the literature involving the mesh category, which is a combinatorial representation of the category of modules over a finite-dimensional associative algebra. We discuss Riedtmann's well-behaved…

Representation Theory · Mathematics 2025-07-08 Viktor Chust , Flávio U. Coelho

In this paper we show that how the representation theory of subcategories (of the category of modules over an Artin algebra) can be connected to the representation theory of all modules over some algebra. The subcategories dealing with are…

Representation Theory · Mathematics 2020-11-03 Rasool Hafezi

In this paper, we consider categories with colored morphisms and functors such that morphisms assigned to morphisms with a common color have a common color. In this paper, we construct a morphism-colored functor such that any…

Category Theory · Mathematics 2016-09-21 Yasuhide Numata

In the preprint arXiv:2511.07900 we proved that there exists a localizing ring $A_M$ for $A$ an associative ring with unit, and $M=\oplus_{i=1}^rM_i$ a direct sum of $r\geq 1$ simple right $A$-modules. For a homomorphism of associative…

Algebraic Geometry · Mathematics 2025-11-13 Arvid Siqveland

An infinite family of association schemes obtained from the general unitary groups acting transitively on the sets of isotropic vectors in the finite unitary spaces are investigated. We compute the parameters and determine the character…

Combinatorics · Mathematics 2024-07-31 Nathaniel Benjamin , Sung Yell Song

Functor morphing provides a method to translate complex representations of automorphism groups of finite modules over finite rings to representations of automorphism groups of functors in some abelian category. In this paper we give an…

Representation Theory · Mathematics 2026-03-30 Ehud Meir

In this paper, we investigate hypergroups which arise from association schemes in a canonical way; this class of hypergroups is called realizable. We first study basic algebraic properties of realizable hypergroups. Then we prove that two…

Combinatorics · Mathematics 2017-04-24 Jaiung Jun

To any model category $\mathcal{M}$, we associate a modular model category, a functor of points $\mathcal{M}[-]:$ Cat $\rightarrow$ Cat, that associates to any small category $\mathcal{C}$ a functor category $\mathcal{M}[\mathcal{C}] =…

Algebraic Geometry · Mathematics 2019-06-25 Renaud Gauthier

For $X$ a complete, reduced, geometrically connected scheme over a perfect field of characteristic $p>0$, we analyze the decomposition of Nori's fundamental group scheme into its local and \'etale parts and raise the question of the…

Algebraic Geometry · Mathematics 2009-05-15 Hélène Esnault , Phùng Hô Hai

In this paper we investigate the construction of bicategories of fractions originally described by D. Pronk: given any bicategory $\mathcal{C}$ together with a suitable class of morphisms $\mathbf{W}$, one can construct a bicategory…

Category Theory · Mathematics 2016-04-21 Matteo Tommasini

In this paper, for any prime $p$, we propose the notion of a $p$-transitive association scheme. This notion aims to generalize the fact that the regular module of a group algebra of a finite group has a unique trivial submodule to the case…

Combinatorics · Mathematics 2020-09-18 Yu Jiang

We develop a representation theory of categories as a means to explore characteristic structures in algebra. Characteristic structures play a critical role in isomorphism testing of groups and algebras, and their construction and…

Group Theory · Mathematics 2025-11-20 Peter A. Brooksbank , Heiko Dietrich , Joshua Maglione , E. A. O'Brien , James B. Wilson

We classify localising subcategories of the stable module category of a finite group that are closed under tensor product with simple (or, equivalently all) modules. One application is a proof of the telescope conjecture in this context.…

Representation Theory · Mathematics 2011-04-18 Dave Benson , Srikanth B. Iyengar , Henning Krause

A Tannakian category is an abelian tensor category equipped with a fiber functor and additional structures which ensure that it is equivalent to the category of representations of some affine groupoid scheme acting on the spectrum of a…

Category Theory · Mathematics 2018-05-10 Daniel Schäppi

Connections between heaps of modules and (affine) modules over rings are explored. This leads to explicit, often constructive, descriptions of some categorical constructions and properties that are implicit in universal algebra and…

Rings and Algebras · Mathematics 2025-10-08 Simion Breaz , Tomasz Brzezinski , Bernard Rybolowicz , Paolo Saracco

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

In this article we are examining extensions and some basic diagrammatic properties of modules, in both cases from a new, "virtual" point of view. As natural background for investigating the kind of problems we are dealing with, the virtual…

Representation Theory · Mathematics 2017-08-15 Stephanos Gekas

Let $R$ be a semilocal principal ideal domain. Two algebraic objects over $R$ in which scalar extension makes sense (e.g. quadratic spaces) are said to be of the same genus if they become isomorphic after extending scalars to all…

Rings and Algebras · Mathematics 2016-01-12 Eva Bayer-Fluckiger , Uriya A. First

Using full images of accessible functors, we prove some results about combinatorial and accessible model categories. In particular, we give an example of a weak factorization system on a locally presentable category which is not accessible.

Category Theory · Mathematics 2022-02-08 Jiří Rosický