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Related papers: Orthogonal projections of discretized sets

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We introduce sparse random projection, an important dimension-reduction tool from machine learning, for the estimation of discrete-choice models with high-dimensional choice sets. Initially, high-dimensional data are compressed into a…

Machine Learning · Statistics 2016-04-21 Khai X. Chiong , Matthew Shum

We prove several results concerning the representation of projections on arbitrary Banach spaces. We also give illustrative examples including an example of a generalized bi-circular projection which can not be written as the average of the…

Functional Analysis · Mathematics 2012-11-02 A. B. Abubaker , Fernanda Botelho , James Jamison

In this paper we prove using quite elementary methods, with a combinatorial nature, two general results related to Marstrand's projection theorem in a quite general formulation over metric spaces under a suitable transversality condition…

Metric Geometry · Mathematics 2024-10-07 Carlos Gustavo Moreira , Sergio Augusto Romaña Ibarra , Waliston Luiz Silva

In this paper we construct a new family of sets based on Diophantine approximation in the Euclidean space, and consider their applications in several problems in harmonic analysis. Our first application is on the Hausdorff dimension of our…

Classical Analysis and ODEs · Mathematics 2026-01-28 Longhui Li , Bochen Liu

We prove an analogue for homogeneous trees and certain affine buildings of a result of Bourgain on pinned distances in sets of positive density in Euclidean spaces. Furthermore, we construct an example of a non-homogeneous tree with…

Combinatorics · Mathematics 2019-07-15 M. Björklund , A. Fish , J. Parkinson

We calculate the measure and Hausdorff dimension of sets of matrices over fields of formal power series with good approximation properties for a restricted set of denominators.

Number Theory · Mathematics 2007-05-23 Simon Kristensen

We generalize some aspects of the theory of compact projections relative to a C*-algebra, to the setting of more general algebras. Our main result is that compact projections are the decreasing limits of `peak projections', and in the…

Operator Algebras · Mathematics 2012-03-19 David P. Blecher , Matthew Neal

We consider a problem posed by Erd\H{o}s, Herzog and Piranian on the maximum product of distances of a point set of order $n$ with a given diameter. We prove that it is sufficient to consider convex polygons and obtain results on the…

Combinatorics · Mathematics 2026-03-10 Stijn Cambie , Arne Decadt , Yanni Dong , Tao Hu , Quanyu Tang

We obtain new lower bounds on the Hausdorff dimension of distance sets and pinned distance sets of planar Borel sets of dimension slightly larger than $1$, improving recent estimates of Keleti and Shmerkin, and of Liu in this regime. In…

Classical Analysis and ODEs · Mathematics 2018-11-09 Pablo Shmerkin

For Borel subsets A and B of the Euclidean n-space the intersection of A with generic rotations and translations of B has often Hausdorff dimension at least dim A + dim B - n. Estimates for the exceptional set of rotations are derived.

Metric Geometry · Mathematics 2018-01-03 Pertti Mattila

Let $\nu$ be a self similar measure on $\mathbb{R}^d$, $d\geq 2$, and let $\pi$ be an orthogonal projection onto a $k$-dimensional subspace. We formulate a criterion on the action of the group generated by the orthogonal parts of the IFS on…

Dynamical Systems · Mathematics 2024-07-24 Amir Algom , Pablo Shmerkin

We prove a weighted Sobolev estimate of the Bergman projection on the Hartogs triangle, where the weight is some power of the distance to the singularity at the boundary. This method also applies to the $n$-dimensional generalization of the…

Complex Variables · Mathematics 2017-06-14 Liwei Chen

The classical Hausdorff dimension of finite or countable sets is zero. We define an analog for finite sets, called finite Hausdorff dimension which is non-trivial. It turns out that a finite bound for the finite Hausdorff dimension…

Discrete Mathematics · Computer Science 2015-08-13 Juan M. Alonso

This paper addresses the question of when projections of a high-dimensional random vector are approximately Gaussian. This problem has been studied previously in the context of high-dimensional data analysis, where the focus is on…

Information Theory · Computer Science 2017-01-02 Galen Reeves

A random vector whose norm and overlap (inner product with an independent copy) concentrates is shown to have random low-dimensional projections that are approximately random Gaussians. Conversely, asymptotically random Gaussian projections…

Probability · Mathematics 2025-12-23 Timothy L. H. Wee , Sekhar Tatikonda

In this paper we study the radial and orthogonal projections and the distance sets of the random Cantor sets $E\subset \mathbb{R}^2 $ which are called Mandelbrot percolation or percolation fractals. We prove that the following assertion…

Dynamical Systems · Mathematics 2013-06-18 Michal Rams , Károly Simon

Generalising a construction of Falconer, we consider classes of $G_\delta$-subsets of $\mathbb{R}^d$ with the property that sets belonging to the class have large Hausdorff dimension and the class is closed under countable intersections. We…

Dynamical Systems · Mathematics 2018-10-15 Tomas Persson

A Clifford algebra model for M"obius geometry is presented. The notion of Ribaucour pairs of orthogonal systems in arbitrary dimensions is introduced, and the structure equations for adapted frames are derived. These equations are…

Differential Geometry · Mathematics 2007-05-23 Alexander I. Bobenko , Udo J. Hertrich-Jeromin

We study the problem of pointwise convegence for the Schr\"odinger operator on $\mathbb R^n$ along time sequences. We show that the sharp counterexample to the sequential Schr\"odinger maximal estimate given recently by Li, Wang and Yan…

Analysis of PDEs · Mathematics 2025-07-15 Chu-Hee Cho , Daniel Eceizabarrena

We discuss Kadison's Carpenter's Theorems in the context of majorisation, and we offer a new proof of his "Theorem 15", that characterizes the set of diagonals of orthogonal projections.

Operator Algebras · Mathematics 2016-08-11 Martín Argerami