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Related papers: Idempotents and the points of the topos of M-sets

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In this note, we deal with the fixed points of an endofunctor $F: \mathcal{C} \longrightarrow \mathcal{C}$. Three classes of fixed points are introduced, and the case when $F$ is an endomorphism of a category with pretopology is…

Category Theory · Mathematics 2017-05-09 Aleksandr Luzhenkov

Let $G$ be a finite group and $N\unlhd G$. In this note, we construct a class poset of $G$ for some cyclic subgroup $C$ of $G$. And we find a relation between $m_{G,N}$ and the Euler characteristic of some nerve spaces of these posets(see…

Group Theory · Mathematics 2018-03-06 Heguo Liu , Xingzhong Xu , Jiping Zhang

By introducing various topologies on the homotopy groups of a topological space, some researchers make these well known notions in algebraic topology more useful and powerful. In this paper, first we recall and review some known topologies…

Algebraic Topology · Mathematics 2026-02-25 Naghme Shahami , Behrooz Mashayekhy

We classify compact 2-connected homogeneous spaces with the same rational cohomology as a product of spheres. This classification relies on spectral sequences, homotopy theory, and representation theory. We then apply this classification to…

Geometric Topology · Mathematics 2007-05-23 Linus Kramer

A candidate for the effective 2-topos is proposed and shown to include the effective 1-topos as its subcategory of 0-types.

Category Theory · Mathematics 2026-01-14 Steve Awodey , Jacopo Emmenegger

In this work, we develop the theory of $k$-idempotent ideals in the setting of dualizing varieties. Several results given previously in \cite{APG} by M. Auslander, M. I. Platzeck, and G. Todorov are extended to this context. Given an ideal…

A 2-categorical generalisation of elementary topos is provided and some of the properties of the yoneda structure it generates are explored. Examples relevant to the globular approach to higher category theory are discussed. This paper also…

Category Theory · Mathematics 2007-05-23 M. Weber

Using methods from commutative algebra and topos-theory, we construct topos-theoretical points for the fppf topology of a scheme. These points are indexed by both a geometric point and a limit ordinal. The resulting stalks of the structure…

Algebraic Geometry · Mathematics 2016-01-27 Stefan Schröer

The finite stable homotopy category S_0 has been suggested as a candidate for a category of perfect complexes over the monoid scheme Spec F_1. We apply a reconstruction theorem from algebraic geometry to S_0, and show that one recovers the…

Algebraic Geometry · Mathematics 2011-06-24 Stella Anevski

We generalize the concepts of locally presentable and accessible categories. Our framework includes such categories as small presheaves over large categories and ind-categories. This generalization is intended for applications in the…

Category Theory · Mathematics 2012-06-05 Boris Chorny , Jiri Rosicky

This note concerns the category $\Box$ of cartesian cubes with connections, equivalently the full subcategory of posets on objects $[1]^n$ with $n \geq 0$. We show that the idempotent completion of $\Box$ consists of finite complete posets.…

Category Theory · Mathematics 2019-03-11 Christian Sattler

In the article \cite{Sim}, H. Simmons describes two monads of interests arising from the dual adjunction between the category of topological spaces and that of (bounded) distributive lattices. These are the open prime filter monad and the…

Category Theory · Mathematics 2025-08-01 Ando Razafindrakoto

In this paper we put forward the definition of particular subsets on a unital C*-algebra, that we call isocones, and which reduce in the commutative case to the set of continuous non-decreasing functions with real values for a partial order…

Operator Algebras · Mathematics 2014-11-18 Fabien Besnard

We show that if a subsemigroup $S$ of the bicyclic monoid ${\mathscr{C}}(p,q)$ contains infinitely many idempotents then $S$ admits only the discrete Hausdorff shift-continuous topology. Also we proof that every right-continuous…

Group Theory · Mathematics 2026-01-06 Adriana Chornenka , Oleg Gutik

Let G be a group and let M be an object of the topos G-Set. We prove that an object X of the category G-Set is isomorphic to some subobject of one of the objects P(M), P(P(M)), P(P(P(M))),... if and only if card X < sup{card P(M), card…

Category Theory · Mathematics 2007-05-23 Apoloniusz Tyszka

Let $M$ be a smooth connected orientable closed surface and $f_0\in C^\infty(M)$ a function having only critical points of the $A_\mu$-types, $\mu\in\mathbb N$. Let ${\mathcal F}={\mathcal F}(f_0)$ be the set of functions $f\in C^\infty(M)$…

Geometric Topology · Mathematics 2017-03-10 Elena A. Kudryavtseva

We define a natural topology on the collection of (equivalence classes up to scaling of) locally finite measures on a homogeneous space and prove that in this topology, pushforwards of certain infinite volume orbits equidistribute in the…

Dynamical Systems · Mathematics 2019-08-15 Uri Shapira , Cheng Zheng

The purpose of this article is to give an exposition of topological properties of spaces of homomorphisms from certain finitely generated discrete groups to Lie groups $G$, and to describe their connections to classical representation…

Algebraic Topology · Mathematics 2016-09-28 Frederick R. Cohen , Mentor Stafa

We study stratifying ideals for rings in the context of relative homological algebra. Using LU-decompositions, which are a special type of twisted products, we give a sufficient condition for an idempotent ideal to be (relative)…

Representation Theory · Mathematics 2014-09-23 Ana Paula Santana , Ivan Yudin

Categorial methods for generating new local algebras from old ones are presented. A direct proof of the differential structure of the prolongations of a manifold is proposed.

Category Theory · Mathematics 2007-09-05 Margherita Barile , Fiorella Barone , Wlodzimierz M. Tulczyjew