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Related papers: Projection inequalities for antichains

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This paper contains new results on two classical topics in fractal geometry: projections, and intersections with affine planes. To keep the notation of the abstract simple, we restrict the discussion to the planar cases of our theorems. Our…

Classical Analysis and ODEs · Mathematics 2016-07-27 Pertti Mattila , Tuomas Orponen

A \emph{subcube partition} is a partition of the Boolean cube $\{0,1\}^n$ into subcubes. A subcube partition is irreducible if the only sub-partitions whose union is a subcube are singletons and the entire partition. A subcube partition is…

We examine caloric measures $\omega$ on general domains in $\mathbb{R}^{n+1} = \mathbb{R}^n\times\mathbb{R}$ (space $\times$ time) from the perspective of geometric measure theory. On one hand, we give a direct proof of a consequence of a…

Classical Analysis and ODEs · Mathematics 2023-07-13 Matthew Badger , Alyssa Genschaw

We study projectional properties of Poisson cut-out sets $E$ in non-Euclidean spaces. In the first Heisenbeg group, endowed with the Kor\'anyi metric, we show that the Hausdorff dimension of the vertical projection $\pi(E)$ (projection…

Probability · Mathematics 2018-12-04 Laurent Dufloux , Ville Suomala

This paper studies the Hausdorff dimension of the intersection of isotropic projections of subsets of $\mathbb{R}^{2n}$, as well as dimension of intersections of sets with isotropic planes. It is shown that if $A$ and $B$ are Borel subsets…

Metric Geometry · Mathematics 2020-01-17 Fernando Roman-Garcia

Cone spherical metrics, defined on compact Riemann surfaces, are conformal metrics with constant curvature one and finitely many cone singularities. Such a metric is termed \textit{reducible} if a developing map of the metric has monodromy…

Differential Geometry · Mathematics 2024-09-25 Yu Feng , Jijian Song , Bin Xu

We make progress on two interrelated problems at the intersection of geometric measure theory, additive combinatorics and harmonic analysis: the discretised sum-product problem, and the dimension of Furstenberg sets. Along the way, we…

Classical Analysis and ODEs · Mathematics 2026-03-24 Tuomas Orponen , Pablo Shmerkin

We investigate the Hausdorff measure and content on a class of quasi self-similar sets that include, for example, graph-directed and sub self-similar and self-conformal sets. We show that any Hausdorff measurable subset of such a set has…

Metric Geometry · Mathematics 2020-03-04 Jasmina Angelevska , Antti Käenmäki , Sascha Troscheit

A strong law of large numbers for $d$-dimensional random projections of the $n$-dimensional cube is derived. It shows that with respect to the Hausdorff distance a properly normalized random projection of $[-1,1]^n$ onto $\mathbb{R}^d$…

Probability · Mathematics 2019-10-08 Zakhar Kabluchko , Joscha Prochno , Christoph Thaele

We study parametrized families of orthogonal projections for which the dimension of the parameter space is strictly less than that of the Grassmann manifold. We answer the natural question of how much the Hausdorff dimension may decrease by…

Classical Analysis and ODEs · Mathematics 2014-10-22 Esa Järvenpää , Maarit Järvenpää , Tamás Keleti

We derive an upper bound for the Assouad dimension of visible parts of self-similar sets generated by iterated function systems with finite rotation groups and satisfying the open set condition. The bound is valid for all visible parts and…

Dynamical Systems · Mathematics 2022-03-21 Esa Järvenpää , Maarit Järvenpää , Ville Suomala , Meng Wu

This paper studies observability inequalities for heat equations on both bounded domains and the whole space $\mathbb{R}^d$. The observation sets are measured by log-type Hausdorff contents, which are induced by certain log-type gauge…

Analysis of PDEs · Mathematics 2024-12-03 Shanlin Huang , Gengsheng Wang , Ming Wang

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

I prove that the visible parts of a compact set in $\mathbb{R}^{n}$, $n \geq 2$, have Hausdorff dimension at most $n - \tfrac{1}{50n}$ from almost every direction.

Classical Analysis and ODEs · Mathematics 2020-12-08 Tuomas Orponen

The method of alternating projections involves orthogonally projecting an element of a Hilbert space onto a collection of closed subspaces. It is known that the resulting sequence always converges in norm if the projections are taken…

Functional Analysis · Mathematics 2018-09-18 Omer Ginat

The set of badly approximable $m \times n $ matrices is known to have Hausdorff dimension $mn $. Each such matrix comes with its own approximation constant $c$, and one can ask for the dimension of the set of badly approximable matrices…

Number Theory · Mathematics 2015-10-12 Ryan Broderick , Dmitry Kleinbock

We prove new bounds on the dimensions of distance sets and pinned distance sets of planar sets. Among other results, we show that if $A\subset\mathbb{R}^2$ is a Borel set of Hausdorff dimension $s>1$, then its distance set has Hausdorff…

Classical Analysis and ODEs · Mathematics 2019-12-17 Tamás Keleti , Pablo Shmerkin

It is shown that if $A \subseteq \mathbb{R}^3$ is a Borel set of Hausdorff dimension $\dim A \in (3/2,5/2)$, then for a.e. $\theta \in [0,2\pi)$ the projection $\pi_{\theta}(A)$ of $A$ onto the 2-dimensional plane orthogonal to…

Classical Analysis and ODEs · Mathematics 2022-12-14 Terence L. J. Harris

In a recent paper, Chan, \L aba, and Pramanik investigated geometric configurations inside thin subsets of the Euclidean set possessing measures with Fourier decay properties. In this paper we ask which configurations can be found inside…

Classical Analysis and ODEs · Mathematics 2016-07-06 Mike Bennett , Alex Iosevich , Krystal Taylor

A Kakeya set in $\mathbb{R}^n$ is a compact set that contains a unit line segment $I_e$ in each direction $e \in S^{n-1}$. The Kakeya conjecture states that any Kakeya set in $\mathbb{R}^n$ has Hausdorff dimension $n$. We consider a…

Classical Analysis and ODEs · Mathematics 2025-06-26 Jonathan M. Fraser , Lijian Yang