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We abstract and generalize homotopical monadicity statements, placing in a single conceptual framework a range of old and recent recognition and characterization principles in iterated loop space theory in classical, equivariant, and…

Algebraic Topology · Mathematics 2024-02-07 Hana Jia Kong , J. Peter May , Foling Zou

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

Given an ordered structure, we study a natural way to extend the order to preorders on type spaces. For definably complete, linearly ordered structures, we give a characterisation of the preorder on the space of 1-types. We apply these…

The oft-neglected issue of the causal structure in the flat spacetime approach to Einstein's theory of gravity is considered. Consistency requires that the flat metric's null cone be respected, but this does not happen automatically. After…

General Relativity and Quantum Cosmology · Physics 2009-09-25 J. Brian Pitts , W. C. Schieve

The spaces D, S and E' over \mathbb{R}^(n) are known to be flat modules over A=\mathbb{C}[\partial_{1},...,\partial_{n}], whereas their duals D', S' and E are known to be injective modules over the same ring. Let A be a Noetherian k-algebra…

Optimization and Control · Mathematics 2013-02-25 Henri Bourlès

We prove strong completeness results for some modal logics with the universal modality, with respect to their topological semantics over 0-dimensional dense-in-themselves metric spaces. We also use failure of compactness to show that, for…

Logic · Mathematics 2020-08-12 Robert Goldblatt , Ian Hodkinson

In this contribution we discuss flat discrete-time nonlinear systems in a general setting including two special subclasses, namely, forward- and backward-flat systems. We relate rank conditions for certain submatrices of the Jacobian of the…

Optimization and Control · Mathematics 2025-11-03 Johannes Schrotshamer , Bernd Kolar , Markus Schöberl

In this paper we define the coarse (co)homology of the complement of a subspace in a metric space, generalizing the coarse (co)homology of Roe. We give a model space which encodes coarse geometric structure of the complement. We also…

Geometric Topology · Mathematics 2023-08-29 Arka Banerjee , Boris Okun

An internal characterization of complete metric mappings (by means of Cauchy nets tied at a point) is given and a construction of the completion of a metric mapping is presented.

General Topology · Mathematics 2020-04-07 Giorgio Nordo

An envelope in a category is a construction that generalizes the operations of "exterior completion", like completion of a locally convex space, or Stone-\v{C}ech compactification of a topological space, or universal enveloping algebra of a…

Functional Analysis · Mathematics 2021-09-01 Sergei Akbarov

This is the first of a series of papers on enriched infinity categories, seeking to reduce enriched higher category theory to the higher algebra of presentable infinity categories, which is better understood and can be approached via…

Category Theory · Mathematics 2020-08-27 John D. Berman

We characterize the finite distributive lattices which admit a complete valuation, that is bijective over a set of consecutive natural numbers, with the additional conditions of completeness (Definition 2.3). We prove that such lattices are…

Discrete Mathematics · Computer Science 2013-09-12 Francesco Marigo

We extend the notion of exact completion on a weakly lex category to elementary doctrines. We show how any such doctrine admits an elementary quotient completion, which freely adds effective quotients and extensional equality. We note that…

Category Theory · Mathematics 2012-06-04 Maria Emilia Maietti , Giuseppe Rosolini

We study $\infty$-modulus on general metric spaces and establish its relation to shortest lengths of paths. This connection was already known for modulus on graphs, but the formulation in metric measure spaces requires more attention to…

Metric Geometry · Mathematics 2021-02-09 Nathan Albin , Jared Hoppis , Pietro Poggi-Corradini , Nageswari Shanmugalingam

This paper obtains a completeness result for inequational reasoning with applicative terms without variables in a setting where the intended semantic models are the full structures, the full type hierarchies over preorders for the base…

Logic in Computer Science · Computer Science 2022-02-18 Lawrence S. Moss , Thomas F. Icard

The paper treats density measures as typical examples of finitely additive measures in $\mathbb{R}^n$. We study their structure and derive basic properties. In addition, estimates for related integrals are provided. The results are applied…

Analysis of PDEs · Mathematics 2026-03-26 Moritz Schönherr , Friedemann Schuricht

M.S. Rao recently investigated some sorts of special filters in distributive pseudocomplemented lattices. In our paper we extend this study to lattices which need neither be distributive nor pseudocomplemented. For this sake we define a…

Rings and Algebras · Mathematics 2023-06-19 Ivan Chajda , Miroslav Kolařík , Helmut Länger

First we present a short overview of the long history of projectively flat Finsler spaces. We give a simple and quite elementary proof of the already known condition for the projective flatness, and we give a criterion for the projective…

Differential Geometry · Mathematics 2015-05-27 T. Q. Binh , D. Cs. Kertész , L. Tamássy

We study a metric-like structure on categories, showing that the concept of the limit of a sequence in a metric space and the concept of the colimit of a sequence in a category have a common generalization. The main concept is a norm on a…

Category Theory · Mathematics 2017-05-30 Wiesław Kubiś

We study a model for gravity in 3+1 dimensions, inspired in general relativity in 2+1 dimensions. In contrast regular general relativity in 3+1 dimensions, the model postulates that space in absence of matter is flat. The requirement that…

General Relativity and Quantum Cosmology · Physics 2011-11-29 Maarten van de Meent