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We exhibit three classes of compactly supported functions which provide reproducing kernels for the Sobolev spaces $H^\delta(\R^d)$ of arbitrary order $\,\delta>d/2.\,$ Our method of construction is based on a new class of oscillatory…

Classical Analysis and ODEs · Mathematics 2017-02-21 Yong-Kum Cho

Any nonpositively curved symmetric space admits a topological compactification, namely the Hadamard compactification. For rank one spaces, this topological compactification can be endowed with a differentiable structure such that the action…

Differential Geometry · Mathematics 2010-06-24 Benoit Kloeckner

Embedding methods for product spaces are powerful techniques for low-distortion and low-dimensional representation of complex data structures. Here, we address the new problem of linear classification in product space forms -- products of…

Machine Learning · Computer Science 2022-01-04 Puoya Tabaghi , Chao Pan , Eli Chien , Jianhao Peng , Olgica Milenkovic

Not all convex functions on $\mathbb{R}^n$ have finite minimizers; some can only be minimized by a sequence as it heads to infinity. In this work, we aim to develop a theory for understanding such minimizers at infinity. We study astral…

Optimization and Control · Mathematics 2025-12-10 Miroslav Dudík , Robert E. Schapire , Matus Telgarsky

We investigate the compact submanifolds in Riemannian space forms of nonnegative sectional curvature that satisfy a lower bound on the Ricci curvature, that bound depending solely on the length of the mean curvature vector of the immersion.…

Differential Geometry · Mathematics 2023-11-06 Marcos Dajczer , Theodoros Vlachos

The strong shape category of compact metrizable spaces (compacta) is very well-studied; extending it to noncompact spaces, however, introduces computational complexity that makes it hard to work with. The fine shape category, as defined by…

Algebraic Topology · Mathematics 2025-10-14 Vladislav Zemlyanoy

Starting from compact symmetric spaces of inner type, we provide infinite families of compact homogeneous spaces carrying invariant non-flat Bismut connections with vanishing Ricci tensor. These examples turn out to be generalized symmetric…

Differential Geometry · Mathematics 2025-01-03 Fabio Podestà , Alberto Raffero

We consider the problem of learning a linear operator $\theta$ between two Hilbert spaces from empirical observations, which we interpret as least squares regression in infinite dimensions. We show that this goal can be reformulated as an…

Statistics Theory · Mathematics 2024-07-11 Mattes Mollenhauer , Nicole Mücke , T. J. Sullivan

The Ricci iteration is a discrete analogue of the Ricci flow. We give the first study of the Ricci iteration on a class of Riemannian manifolds that are not K\"ahler. The Ricci iteration in the non-K\"ahler setting exhibits new phenomena.…

Differential Geometry · Mathematics 2019-02-19 Artem Pulemotov , Yanir A. Rubinstein

In this article we introduce a new class of weighted sequence spaces of Sobolev type and prove several compact embedding theorems for them. It is our contention that the chosen class is general enough so as to allow applications in various…

Functional Analysis · Mathematics 2025-03-27 Pierre-A. Vuillermot

For a topological space $X$ its reflection in a class $\mathsf T$ of topological spaces is a pair $(\mathsf T X,i_X)$ consisting of a space $\mathsf T X\in\mathsf T$ and continuous map $i_X:X\to \mathsf T X$ such that for any continuous map…

General Topology · Mathematics 2021-11-01 Taras Banakh

We describe the singular locus of the compactification of the moduli space $R_{g,l}$ of curves of genus $g$ paired with an $l$-torsion point in their Jacobian. Generalising previous work for $l\le 2$, we also describe the sublocus of…

Algebraic Geometry · Mathematics 2015-02-27 Alessandro Chiodo , Gavril Farkas

We consider some distinguished classes of elements of a multiplicative lattice endowed with coarse lower topologies, and call them lower spaces. The primary objective of this paper is to study the topological properties of these lower…

Rings and Algebras · Mathematics 2024-07-08 Amartya Goswami

We show that for any weakly reflective submanifold of a compact isotropy irreducible Riemannian homogeneous space its inverse image under the parallel transport map is an infinite dimensional weakly reflective PF submanifold of a Hilbert…

Differential Geometry · Mathematics 2020-03-11 Masahiro Morimoto

We provide examples of nonseparable compact spaces with the property that any continuous image which is homeomorphic to a finite product of spaces has a maximal prescribed number of nonseparable factors.

General Topology · Mathematics 2014-09-15 Antonio Avilés

Klartag's needle decomposition technique enables one to obtain strong isoperimetric inequalities on Riemannian manifolds other than the classical known examples. As a result, in this paper, we obtain sharp isoperimetric inequalities for…

Metric Geometry · Mathematics 2021-07-13 Yashar Memarian

To any metric spaces there is an associated metric profile. The rectifiability of the metric profile gives a good notion of curvature of a sub-Riemannian space. We shall say that a curvature class is the rectifiability class of the metric…

Metric Geometry · Mathematics 2007-05-23 Marius Buliga

In this short note we provide several conjectures on the regularity of measured Gromov-Hausdorff limit spaces of Riemannian manifolds with Ricci curvature bounded below, from the point of view of the synthetic treatment of lower bounds on…

Differential Geometry · Mathematics 2020-04-02 Shouhei Honda

There exists a d-minimal expansion of the $\mathbb R$-vector space over $\mathbb R$ which defines every sequence. In this paper, we prove this assertion and the following more general assertion: Let $\mathcal R$ be either the ordered…

Logic · Mathematics 2024-09-09 Masato Fujita

Rectangular designs are classified as regular, Latin regular, semiregular, Latin semiregular and singular designs. Some series of selfdual as well as alpharesolvable designs are obtained using matrix approaches which belong to the above…

Combinatorics · Mathematics 2022-06-02 Mithilesh Kumar Singh , Shyam Saurabh