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Related papers: Measure theoretic laws for lim sup sets

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In this paper we investigate the metrical theory of Diophantine approximation associated with linear forms that are simultaneously small for infinitely many integer vectors; i.e. forms which are close to the origin. A complete…

Number Theory · Mathematics 2009-10-20 Mumtaz Hussain , Jason Levesley

Fundamental questions in Diophantine approximation are related to the Hausdorff dimension of sets of the form $\{x\in \mathbb{R}: \delta_x = \delta\}$, where $\delta \geq 1$ and $\delta_x$ is the Diophantine approximation rate of an…

Number Theory · Mathematics 2009-03-13 Julien Barral , Stephane Seuret

A subset of a topological space is said to be \emph{universally measurable} if it is measured by the completion of each countably additive $\sigma$-finite Borel measure on the space, and \emph{universally null} if it has measure zero for…

Logic · Mathematics 2010-03-15 Paul Larson , Itay Neeman , Saharon Shelah

The use of Hausdorff measures and dimension in the theory of Diophantine approximation dates back to the 1920s with the theorems of Jarnik and Besicovitch regarding well-approximable and badly-approximable points. In this paper we consider…

Number Theory · Mathematics 2016-04-01 Victor Beresnevich , Sanju Velani

Following the development of weighted asymptotic approximation properties of matrices, we introduce the analogous uniform approximation properties (that is, study the improvability of Dirichlet's Theorem). An added feature is the use of…

Number Theory · Mathematics 2022-02-25 Dmitry Kleinbock , Anurag Rao

Let $\cal C$ be a non--degenerate planar curve and for a real, positive decreasing function $\psi$ let $\cal C(\psi)$ denote the set of simultaneously $\psi$--approximable points lying on $\cal C$. We show that $\cal C$ is of Khintchine…

Number Theory · Mathematics 2007-05-23 Victor Beresnevich , Detta Dickinson , Sanju Velani

A Hausdorff measure version of W.M. Schmidt's inhomogeneous, linear forms theorem in metric number theory is established. The key ingredient is a `slicing' technique motivated by a standard result in geometric measure theory. In short,…

Number Theory · Mathematics 2007-05-23 Victor Beresnevich , Sanju Velani

We consider approximation properties of real points by uniformly distributed sequences. Under some assumptions on the approximation functions, we prove a Khintchine-type $0$-$1$ dichotomy law. We establish a new connection between uniform…

Number Theory · Mathematics 2025-07-10 Gerardo González Robert , Mumtaz Hussain , Nikita Shulga , Benjamin Ward

Motivated by ideas from the model theory of metric structures, we introduce a metric set theory, $\mathsf{MSE}$, which takes bounded quantification as primitive and consists of a natural metric extensionality axiom (the distance between two…

Logic · Mathematics 2023-02-07 James Hanson

In this paper we prove an upper bound on the "size" of the set of multiplicatively $\psi$-approximable points in $\mathbb R^d$ for $d>1$ in terms of $f$-dimensional Hausdorff measure. This upper bound exactly complements the known lower…

Number Theory · Mathematics 2018-03-12 Mumtaz Hussain , David Simmons

Analogues of the classical theorems of Khintchine, Jarnik and Jarnik-Besicovitch in the metrical theory of Diophantine approximation are established for quaternions by applying results on the measure of general `lim sup' sets.

Number Theory · Mathematics 2019-02-20 Maurice Dodson , Brent Everitt

Let $F \subseteq [0,1]$ be a set that supports a probability measure $\mu$ with the property that $ |\widehat{\mu}(t)| \ll (\log |t|)^{-A}$ for some constant $ A > 0 $. Let $\mathcal{A}= (q_n)_{n\in \mathbb{N}} $ be a sequence of natural…

Number Theory · Mathematics 2019-11-26 Andrew D. Pollington , Sanju Velani , Agamemnon Zafeiropoulos , Evgeniy Zorin

In this paper, we present a general principle for the Lebesgue measure theory of limsup sets defined by rectangles under the hypothesis of ubiquity for rectangles.

Number Theory · Mathematics 2023-03-31 Dmitry Kleinbock , Baowei Wang

Let $K\subset\mathbb R^d$ be a compact subset equipped with a $\delta$-Ahlfors regular measure $\mu$. For any $\tau>1/d$ and any ``inhomogeneous'' vector $\boldsymbol{\theta}\in\mathbb R^d$, let $W_d(\psi_\tau,\boldsymbol{\theta})$ denote…

Number Theory · Mathematics 2026-02-17 Yubin He , Lingmin Liao

We extend the Duffin--Schaeffer conjecture to the setting of systems of $m$ linear forms in $n$ variables. That is, we establish a criterion to determine whether, for a given rate of approximation, almost all or almost no $n$-by-$m$ systems…

Number Theory · Mathematics 2023-01-25 Felipe A. Ramirez

We introduce a natural definition of $L^p$-convergence of maps, $p \ge 1$, in the case where the domain is a convergent sequence of measured metric space with respect to the measured Gromov-Hausdorff topology and the target is a…

Differential Geometry · Mathematics 2007-05-23 Kazuhiro Kuwae , Takashi Shioya

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

We prove a version of the implicit function theorem for Lipschitz mappings $f:\mathbb{R}^{n+m}\supset A \to X$ into arbitrary metric spaces. As long as the pull-back of the Hausdorff content $\mathcal{H}_{\infty}^n$ by $f$ has positive…

Geometric Topology · Mathematics 2019-03-26 Piotr Hajłasz , Scott Zimmerman

In this paper, we investigate the Hausdorff dimension of naturally occurring sets of inhomogeneous well-approximable points with a sequence of real invertible matrices $\mathcal{A}=(A_n)_{n\in\mathbb{N}}$. Specifically, for a given point…

Number Theory · Mathematics 2025-12-17 Zhang-nan Hu , Junjie Huang , Bing Li , Jun Wu

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