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Related papers: Hereditarily Non Uniformly Perfect Sets

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Compact sets in constructive mathematics capture our intuition of what computable subsets of the plane (or any other complete metric space) ought to be. A good representation of compact sets provides an efficient means of creating and…

Logic in Computer Science · Computer Science 2010-08-04 Russell O'Connor

In the present paper we characterize the surjective isometries of the space of compact, convex subsets of proper, geodesically complete CAT(0)-spaces in which geodesics do not split, endowed with the Hausdorff metric. Moreover, an analogue…

Metric Geometry · Mathematics 2007-05-23 Thomas Foertsch

We show that in $\mathbb{R}^d$ there are purely unrectifiable sets of Hausdorff (and even box counting) dimension $d-1$ which are not tube null, settling a question of Carbery, Soria and Vargas, and improving a number of results by the same…

Classical Analysis and ODEs · Mathematics 2015-11-06 Pablo Shmerkin , Ville Suomala

A set $X \subseteq 2^\omega$ with positive measure contains a perfect subset. We study such perfect subsets from the viewpoint of computability and prove that these sets can have weak computational strength. Then we connect the existence of…

Logic · Mathematics 2018-11-05 Chitat Chong , Wei Li , Wei Wang , Yue Yang

We study the Hausdorff dimension and measures of full Hausdorff dimension for a compact invariant set of an expanding nonconformal map on the torus given by an integer-valued diagonal matrix. The Hausdorff dimension of a "general Sierpinski…

Dynamical Systems · Mathematics 2008-04-02 Yuki Yayama

Given any dimension function $h$, we construct a perfect set $E \subseteq \mathbb{R}$ of zero $h$-Hausdorff measure, that contains any finite polynomial pattern. This is achieved as a special case of a more general construction in which we…

Classical Analysis and ODEs · Mathematics 2020-02-19 Ursula Molter , Alexia Yavicoli

We prove the continuity of logarithmic capacity under Hausdorff convergence of uniformly perfect planar sets. The continuity holds when the Hausdorff distance to the limit set tends to zero at sufficiently rapid rate, compared to the decay…

Complex Variables · Mathematics 2021-09-15 Sergei Kalmykov , Leonid V. Kovalev

We consider (not self-similar) Cantor sets defined by a sequence of piecewise linear functions. We prove that the dimension of the harmonic measure on such a set is strictly smaller than its Hausdorff dimension. Some Hausdorff measure…

Classical Analysis and ODEs · Mathematics 2013-03-19 Athanasios Batakis , Anna Zdunik

It is shown to be consistent with set theory that the uniformity invariant for Lebesgue measure is strictly greater than the corresponding invariant for Hausdorff r-dimensional measure where 0<r<1.

Logic · Mathematics 2016-08-16 Saharon Shelah , Juris Steprāns

In this paper, the concept of weakly uniform perfectness is considered. As an analogue of the theory of uniform perfectness, we obtain the relationships between weakly uniform perfectness and Bergman kernel, Poincar\'e metric and Hausdorff…

Complex Variables · Mathematics 2025-09-01 Zhiyuan Zheng

In this paper we study local stable/unstable sets of sensitive homeomorphisms with the shadowing property defined on compact metric spaces. We prove that local stable/unstable sets always contain a compact and perfect subset of the space.…

Dynamical Systems · Mathematics 2024-10-22 Mayara Antunes , Bernardo Carvalho , Margoth Tacuri

The paper studies hereditarily complete superintuitionistic deductive systems, that is, the deductive system which logic is an extension of the intuitionistic propositional logic. It is proven that for deductive systems a criterion of…

Logic · Mathematics 2016-11-16 Alex Citkin

A separable metric space X is an H-null set if any uniformly continuous image of X has Hausdorff dimension zero. upper H-null, directed P-null and P-null sets are defined likewise, with other fractal dimensions in place of Hausdorff…

Logic · Mathematics 2012-08-29 Ondrej Zindulka

A topological group G is h-complete if every continuous homomorphic image of G is (Raikov-)complete; we say that G is hereditarily h-complete if every closed subgroup of G is h-complete. In this paper, we establish open-map properties of…

General Topology · Mathematics 2011-09-27 Gábor Lukács

We consider N-tensor powers of a positive Hermitian line bundle L over a non-compact complex manifold X. In the compact case, B. Shiffman and S. Zelditch proved that the zeros of random sections become asymptotically uniformly distributed…

Complex Variables · Mathematics 2012-10-23 Tien-Cuong Dinh , George Marinescu , Viktoria Schmidt

The dimension spectrum of a conformal iterated function system (CIFS) is the set of all Hausdorff dimensions of its various subsystem limit sets. This brief note provides two constructions -- (i) a compact perfect set that cannot be…

Dynamical Systems · Mathematics 2023-02-24 Tushar Das , David Simmons

P.J. Nyikos has asked whether it is consistent that every hereditarily normal manifold of dimension > 1 is metrizable, and proved it is if one assumes the consistency of a supercompact cardinal, and, in addition, that the manifold is…

General Topology · Mathematics 2016-07-19 Alan Dow , Franklin D. Tall

We investigate variants of the Erd\H{o}s similarity problem for Cantor sets. We prove that under a mild Hausdorff or packing logarithmic dimension assumption, Cantor sets are not full measure universal, significantly improving the known…

Classical Analysis and ODEs · Mathematics 2025-12-22 Pablo Shmerkin , Alexia Yavicoli

In the present article we describe how one can define Hausdorff measure allowing empty elements in coverings, and using infinite countable coverings only. In addition, we discuss how the use of different nonequivalent interpretations of the…

General Mathematics · Mathematics 2017-10-24 Alexey A. Tuzhilin

In this paper we consider the problem of characterization of topological spaces that embed into countably compact Hausdorff spaces. We study the separation axioms of subspaces of countably compact Hausdorff spaces and construct an example…

General Topology · Mathematics 2019-06-12 Taras Banakh , Serhii Bardyla , Alex Ravsky