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Related papers: Universal Sets for Projections

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We present strong versions of Marstrand's projection theorems and other related theorems. For example, if E is a plane set of positive and finite s-dimensional Hausdorff measure, there is a set X of directions of Lebesgue measure 0, such…

Metric Geometry · Mathematics 2015-11-19 Kenneth Falconer , Pertti Mattila

We prove a universal projection theorem, giving conditions on a parametrized family of maps $\Pi_\lambda : X \to \mathbb{R}^d$ and a collection M of measures on X under which for almost every $\lambda$ equality $\dim_H \Pi_\lambda \mu =…

Dynamical Systems · Mathematics 2025-09-24 Balázs Bárány , Károly Simon , Adam Śpiewak

We consider several classical results related to the Hausdorff dimension of exceptional sets of orthogonal projections and try to find out whether they have reasonable formulations in terms of packing dimension. We also investigate the…

Classical Analysis and ODEs · Mathematics 2015-05-19 Tuomas Orponen

Marstrand's theorem states that applying a generic rotation to a planar set $A$ before projecting it orthogonally to the $x$-axis almost surely gives an image with the maximal possible dimension $\min(1, \dim A)$. We first prove, using the…

Metric Geometry · Mathematics 2023-06-05 Anton Lukyanenko , Annina Iseli

We consider Marstrand type projection theorems for closest-point projections in the normed space $\mathbb{R}^2$. We prove that if a norm on $\mathbb{R}^2$ is regular enough, then the analogues of the well-known statements from the Euclidean…

Metric Geometry · Mathematics 2018-03-01 Zoltán M. Balogh , Annina Iseli

Marstrand's celebrated projection theorem gives the Hausdorff dimension of the orthogonal projection of a Borel set in Euclidean space for almost all orthogonal projections. It is straightforward to see that sets for which the Fourier and…

Classical Analysis and ODEs · Mathematics 2024-06-21 Jonathan M. Fraser , Ana E. de Orellana

We consider the Assouad dimensions of orthogonal projections of planar sets onto lines. Our investigation covers both general and self-similar sets. For general sets, the main result is the following: if a set in the plane has Assouad…

Classical Analysis and ODEs · Mathematics 2017-05-04 Jonathan M. Fraser , Tuomas Orponen

We study projections onto non-degenerate one-dimensional families of lines and planes in $\mathbb{R}^{3}$. Using the classical potential theoretic approach of R. Kaufman, one can show that the Hausdorff dimension of at most…

Classical Analysis and ODEs · Mathematics 2014-11-27 Katrin Fässler , Tuomas Orponen

Assuming $V=L$, we construct a plane set $E$ of Hausdorff dimension $1$ whose every orthogonal projection onto straight lines through the origin has Hausdorff dimension $0$. This is a counterexample to J. M. Marstrand's seminal projection…

Logic · Mathematics 2023-01-18 Linus Richter

In this paper we use the theory of computing to study fractal dimensions of projections in Euclidean spaces. A fundamental result in fractal geometry is Marstrand's projection theorem, which shows that for every analytic set E, for almost…

Computational Complexity · Computer Science 2021-11-15 Neil Lutz , D. M. Stull

Marstrand's projection theorem from $1954$ states that if $K \subset \mathbb{R}^{3}$ is an analytic set, then, for $\mathcal{H}^{2}$ almost every $e \in S^{2}$, the orthogonal projection $\pi_{e}(K)$ of $K$ to the line spanned by $e$ has…

Classical Analysis and ODEs · Mathematics 2021-07-05 Antti Käenmäki , Tuomas Orponen , Laura Venieri

We establish a refinement of Marstrand's projection theorem for Hausdorff dimension functions finer than the usual power functions, including an analogue of Marstrand's Theorem for logarithmic Hausdorff dimension.

Metric Geometry · Mathematics 2018-12-17 Victor Beresnevich , Kenneth Falconer , Sanju Velani , Agamemnon Zafeiropoulos

We show that, almost surely, the Hausdorff dimension $s_0$ of a random covering set is preserved under all orthogonal projections to linear subspaces with dimension $k>s_0$. The result holds for random covering sets with a generating…

Classical Analysis and ODEs · Mathematics 2015-05-11 Changhao Chen , Henna Koivusalo , Bing Li , Ville Suomala

The classical Besicovitch projection theorem states that if a planar set $E$ with finite length is purely unrectifiable, then almost all orthogonal projections of $E$ have zero length. We prove a quantitative version of this result: if…

Classical Analysis and ODEs · Mathematics 2025-07-28 Damian Dąbrowski

The point-to-set principle \cite{LutLut17} characterizes the Hausdorff dimension of a subset $E\subseteq\R^n$ by the \textit{effective} (or algorithmic) dimension of its individual points. This characterization has been used to prove…

Computational Complexity · Computer Science 2021-05-13 D. M. Stull

In 1954 Marstrand proved that if K is a subset of R^2 with Hausdorff dimension greater than 1, then its one-dimensional projection has positive Lebesgue measure for almost-all directions. In this article, we give a combinatorial proof of…

Dynamical Systems · Mathematics 2020-04-21 Yuri Lima , Carlos Gustavo Moreira

This paper extends some results of [M5] and [M3], in particular, removing assumptions of positive lower density. We give conditions on a general family $P_{\lambda}:\mathbb{R}^{n}\to\mathbb{R}^{m}, \lambda \in \Lambda,$ of orthogonal…

Classical Analysis and ODEs · Mathematics 2023-10-12 Pertti Mattila

We prove a general nonlinear projection theorem for Assouad dimension. This theorem has several applications including to distance sets, radial projections, and sum-product phenomena. In the setting of distance sets we are able to…

Metric Geometry · Mathematics 2024-03-20 Jonathan M. Fraser

We give conditions on a general family $P_{\lambda}:\R^n\to\R^m, \lambda \in \Lambda,$ of orthogonal projections which guarantee that the Hausdorff dimension formula $\dim A\cap P_{\lambda}^{-1}\{u\}=s-m$ holds generically for measurable…

Classical Analysis and ODEs · Mathematics 2020-06-09 Pertti Mattila

We prove that if $E$ is a planar self-similar set with similarity dimension $d$ whose defining maps generate a dense set of rotations, then the $d$-dimensional Hausdorff measure of the orthogonal projection of $E$ onto any line is zero. We…

Classical Analysis and ODEs · Mathematics 2007-05-23 Kemal Ilgar Eroglu
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