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The problem of bi-equivariant extension of continuous maps of binary $G$-spaces is considered. The concept of a structural map of distributive binary $G$-spaces is introduced, and a theorem on the bi-equivariant extension of structural maps…

General Topology · Mathematics 2025-09-11 Pavel S. Gevorgyan

We formalize the concept of a centralizer-respecting homomorphism, surjective homomorphisms which are equivariant with respect to taking the centralizer of a subgroup. There is a functor from the category of centralizer-respecting…

Group Theory · Mathematics 2026-05-15 William Cocke , Mark L. Lewis , Ryan McCulloch

We construct explicit models of universal $H \mathbb{Z}[J^{-1}]$-acyclic spaces $\mathcal M$, for any subset $J$ of the prime numbers. The corresponding nullification functors provide thus plus construction functors for ordinary homology…

Algebraic Topology · Mathematics 2025-12-10 Guille Carrión Santiago , Ramón Flores , Jérôme Scherer

Parametric models in vector spaces are shown to possess an associated linear map. This linear operator leads directly to reproducing kernel Hilbert spaces and affine- / linear- representations in terms of tensor products. From the…

Numerical Analysis · Mathematics 2018-06-19 Hermann G. Matthies , Roger Ohayon

Morphisms, structure preserving maps, are everywhere in Mathematics as useful tools for thinking and problem solving, or as objects to study. Here, we argue that the idea of operations being compatible across two domains goes beyond its…

History and Overview · Mathematics 2025-06-11 Attila Egri-Nagy , Miklós Hoffmann

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

Milnor's fibration theorem and its generalizations play a central role in the study of singularities of complex and real analytic maps. In the complex analytic case, the Milnor fibration on the sphere is always given by the normalized map…

Complex Variables · Mathematics 2026-01-08 José Luis Cisneros Molina , Aurélio Menegon

Let S be the spectrum of a discrete valuation ring with function field K. Let X be a scheme over S. We will say that X is semi-factorial over S if each invertible sheaf on the generic fiber X_K can be extended to an invertible sheaf on X.…

Algebraic Geometry · Mathematics 2011-03-04 Cédric Pépin

We show that factorization systems, both strict and orthogonal, can be equivalently described as double categories satisfying certain properties. This provides conceptual reasons for why the category of sets and partial maps or the category…

Category Theory · Mathematics 2023-06-13 Miloslav Štěpán

We prove fibration theorems \`a la Milnor for differentiable real maps with non isolated critical values. We study the situation for maps with linear discriminant, and prove that the concept of d-regularity is the key point for the…

Algebraic Geometry · Mathematics 2020-02-18 JosÉ Luis Cisneros-Molina , AurÉlio Menegon , JosÉ Seade , Jawad Snoussi

Fractals equipped with intrinsic arithmetic lead to a natural definition of differentiation, integration and complex numbers. Applying the formalism to the problem of a Fourier transform on fractals we show that the resulting transform has…

Mathematical Physics · Physics 2016-07-26 Diederik Aerts , Marek Czachor , Maciej Kuna

We construct a globalization of Ferrand's norm functor over rings which generalizes it to the setting of a finite locally free morphism of schemes $T\to S$ of constant rank. It sends quasi-coherent modules over $T$ to quasi-coherent modules…

Algebraic Geometry · Mathematics 2024-12-12 Philippe Gille , Erhard Neher , Cameron Ruether

We examine the structure of Farey maps, which are a class of maps (graph embeddings on surfaces) that have received significant attention recently. We describe how they are related to each other through regular coverings and parallel…

Combinatorics · Mathematics 2021-11-19 Margaret Stanier

In this paper we revisit two concepts which were originally introduced by Aschbacher and are crucial in the theory of saturated fusion systems: Firstly, we give a new approach to defining the centralizer of a normal subsystem. Secondly, we…

Group Theory · Mathematics 2018-07-05 Ellen Henke

One way of interpreting a left Kan extension is as taking a kind of "partial colimit", whereby one replaces parts of a diagram by their colimits. We make this intuition precise by means of the "partial evaluations" sitting in the so-called…

Category Theory · Mathematics 2024-04-15 Paolo Perrone , Walter Tholen

We prove that the vanishing of the functoriality morphism for the \'etale fundamental group between smooth projective varieties over an algebraically closed field of characteristic $p>0$ forces the same property for the fundamental groups…

Algebraic Geometry · Mathematics 2017-05-26 Hélène Esnault , Vasudevan Srinivas

In this paper we make an overview of results relating the recent "discoveries" in differential geometry, such as higher structures and differential graded manifolds with some natural problems coming from mechanics. We explain that a lot of…

Mathematical Physics · Physics 2021-03-17 Vladimir Salnikov , Aziz Hamdouni , Daria Loziienko

We study the functorial and growth properties of closed orbits for maps. By viewing an arbitrary sequence as the orbit-counting function for a map, iterates and Cartesian products of maps define new transformations between integer…

Number Theory · Mathematics 2009-09-22 Apisit Pakapongpun , Thomas Ward

The notion of a regular operator with compact supports between function spaces is introduced. On that base we obtain a characterization of absolute extensors for zero-dimensional spaces in terms of regular extension operators having compact…

General Topology · Mathematics 2009-04-29 Vesko Valov

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