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The article deals with plastic and non-plastic sub-spaces $A$ of the real line ${\mathbb{R}}$ with the usual Euclidean metric $d$. It investigates non-expansive bijections, proves properties of such maps and demonstrates their relevance by…

Functional Analysis · Mathematics 2023-11-13 Dirk Langemann , Olesia Zavarzina

Many machine learning methods look for low-dimensional representations of the data. The underlying subspace can be estimated by first choosing a dimension $q$ and then optimizing a certain objective function over the space of…

Machine Learning · Statistics 2025-12-19 Tom Szwagier , Xavier Pennec

In an earlier work, we proposed a generalization for the Apollonian packing in arbitrary dimensions and showed that the resulting object in four, five, and six dimensions have properties consistent with the Apollonian circle and sphere…

Group Theory · Mathematics 2019-01-15 Arthur Baragar

We study the sphere packing problem in Euclidean space where we impose additional constraints on the separations of the center points. We prove that any sphere packing in dimension $48$, with spheres of radii $r$, such that no two centers…

Number Theory · Mathematics 2025-03-05 Felipe Gonçalves , Guilherme Vedana

We consider cosmological solutions of string and M-theory compactified to four dimensions by giving a general prescription to construct four-dimensional modular cosmologies with two commuting Killing vectors from vacuum solutions. By…

High Energy Physics - Theory · Physics 2009-10-31 A. Feinstein , M. A. Vazquez-Mozo

We prove that for all integers $2\leq m\leq d-1$, there exists doubling measures on $\mathbb{R}^d$ with full support that are $m$-rectifiable and purely $(m-1)$-unrectifiable in the sense of Federer (i.e. without assuming…

Metric Geometry · Mathematics 2025-05-09 Matthew Badger , Raanan Schul

If $g$ is a map from a space $X$ into $\mathbb R^m$ and $q$ is an integer, let $B_{q,d,m}(g)$ be the set of all lines $\Pi^d\subset\mathbb R^m$ such that $|g^{-1}(\Pi^d)|\geq q$. Let also $\mathcal H(q,d,m,k)$ denote the maps $g\colon…

General Topology · Mathematics 2010-11-09 S. Bogataya , S. Bogatyi , V. Valov

Every compact symmetric space $M$ admits a dual noncompact symmetric space $\check{M}$. When $M$ is a generalized Grassmannian, we can view $\check{M}$ as a open submanifold of it consisting of space-like subspaces \cite{HL}. Motivated from…

Algebraic Geometry · Mathematics 2018-11-08 Yunxia Chen , Yongdong Huang , Naichung Conan Leung

This paper considers an extension of origami geometry to the case of "folding" a three dimensional (3D) space along a plane. First, all possible incidence constraints between given points, lines and planes are analyzed by using the geometry…

History and Overview · Mathematics 2018-09-18 Jorge C. Lucero

Equations for submanifolds, which correspond to embeddings of the four-dimensional FRW universes in five-dimensional pseudo-Euclidean spaces, are presented in convenient form in general case. Several specific examples are considered.

General Relativity and Quantum Cosmology · Physics 2012-03-13 Igor E. Gulamov , Mikhail N. Smolyakov

Representing graphs as sets of node embeddings in certain curved Riemannian manifolds has recently gained momentum in machine learning due to their desirable geometric inductive biases, e.g., hierarchical structures benefit from hyperbolic…

Machine Learning · Computer Science 2020-06-09 Calin Cruceru , Gary Bécigneul , Octavian-Eugen Ganea

The goal of this article is to investigate nontrivial $m$-quasi-Einstein manifolds globally conformal to an $n$-dimensional Euclidean space. By considering such manifolds, whose conformal factors and potential functions are invariant under…

Differential Geometry · Mathematics 2019-12-09 Ernani Ribeiro , Keti Tenenblat

We consider the problem of finding an optimal transport plan between an absolutely continuous measure $\mu$ on $\mathcal{X} \subset \mathbb{R}^d$ and a finitely supported measure $\nu$ on $\mathbb{R}^d$ when the transport cost is the…

Numerical Analysis · Mathematics 2018-10-08 Valentin Hartmann , Dominic Schuhmacher

We show that compact Riemannian manifolds, regarded as metric spaces with their global geodesic distance, cannot contain a number of rigid structures such as (a) arbitrarily large regular simplices or (b) arbitrarily long sequences of…

Metric Geometry · Mathematics 2021-01-06 Alexandru Chirvasitu

In the following we construct spaces of dimension $(n\pm \varepsilon)$ lying in the neighborhood of $\mathbb{Z}^n, \mathbb{Z}^n$ in the context of the $(n-\varepsilon)$-expansion. We provide means and criteria to deform the spaces of…

High Energy Physics - Theory · Physics 2017-12-28 Manfred Requardt

\textit{Parastichies} are spiral patterns observed in plants and numerical patterns generated using golden angle method. We generalize this method by using Markoff theory and the theory of product of linear forms, to obtain a theory for…

Number Theory · Mathematics 2024-09-27 S. E. Graiff Zurita , B. Kane , R. Oishi-Tomiyasu

In this paper we extend the construction of the Niemytzki plane to dimension $n \geq 3$. Further, we consider a poset of topologies on the closed $n$-dimensional Euclidean half-space similar to one from \cite{AAK} which is related to the…

General Topology · Mathematics 2024-11-19 Vitalij A. Chatyrko

Recent advances in computer vision and machine learning suggest that a wide range of problems can be addressed more appropriately by considering non-Euclidean geometry. In this paper we explore sparse dictionary learning over the space of…

Computer Vision and Pattern Recognition · Computer Science 2013-10-21 Mehrtash Harandi , Conrad Sanderson , Chunhua Shen , Brian C. Lovell

In the context of clustering, we consider a generative model in a Euclidean ambient space with clusters of different shapes, dimensions, sizes and densities. In an asymptotic setting where the number of points becomes large, we obtain…

Machine Learning · Statistics 2009-09-15 Ery Arias-Castro

Let M be a complete non-compact connected Riemannian n-dimensional manifold. We first prove that, for any fixed point p in M, the radial Ricci curvature of M at p is bounded from below by the radial curvature function of some non-compact…

Differential Geometry · Mathematics 2011-06-09 Kei Kondo , Minoru Tanaka