Measure and dimension functions: measurability and densities

1997 ◽  
Vol 121 (1) ◽  
pp. 81-100 ◽  
Author(s):  
PERTTI MATTILA ◽  
R. DANIEL MAULDIN
Keyword(s):  
Hausdorff Measure ◽  
Measure Theory ◽  
Packing Dimension ◽  
Dimension Function ◽  
Packing Measure ◽  
Compact Sets ◽  
Analytic Sets ◽  
Dimension Functions ◽  
Definition Of ◽  
Borel Measurable

During the past several years, new types of geometric measure and dimension have been introduced; the packing measure and dimension, see [Su], [Tr] and [TT1]. These notions are playing an increasingly prevalent role in various aspects of dynamics and measure theory. Packing measure is a sort of dual of Hausdorff measure in that it is defined in terms of packings rather than coverings. However, in contrast to Hausdorff measure, the usual definition of packing measure requires two limiting procedures, first the construction of a premeasure and then a second standard limiting process to obtain the measure. This makes packing measure somewhat delicate to deal with. The question arises as to whether there is some simpler method for defining packing measure and dimension. In this paper, we find a basic limitation on this possibility. We do this by determining the descriptive set-theoretic complexity of the packing functions. Whereas the Hausdorff dimension function on the space of compact sets is Borel measurable, the packing dimension function is not. On the other hand, we show that the packing dimension functions are measurable with respect to the σ-algebra generated by the analytic sets. Thus, the usual sorts of measurability properties used in connection with Hausdorff measure, for example measures of sections and projections, remain true for packing measure.

FRACTAL STOKES’ THEOREM BASED ON INTEGRALS ON FRACTAL MANIFOLDS

Fractals ◽  
2020 ◽  
Vol 28 (01) ◽  
pp. 2050010
Author(s):  
JUNRU WU ◽  
CHENGYUAN WANG
Keyword(s):  
Hausdorff Measure ◽  
Measure Theory ◽  
Lower Dimension ◽  
Riemann Integral ◽  
Fractal Sets ◽  
Gauss Theorem ◽  
Variable Substitution ◽  
Definition Of ◽  
Substitution Theorem

In this paper, with the Hausdorff measure, the Hausdorff integral on fractal sets with one or lower dimension is firstly introduced via measure theory. Then the definition of the integral on fractal sets in [Formula: see text] is given. With the variable substitution theorem in the Riemann integral generalized to the integral on fractal sets, the integral on fractal manifolds is defined. As a result, with the generalization of Gauss’ theorem, Stokes’ theorem is generalized to the integral on fractal manifolds in [Formula: see text].

scholarly journals Hausdorff theory of dual approximation on planar curves

2018 ◽  
Vol 2018 (740) ◽  
pp. 63-76 ◽  
Author(s):  
Jing-Jing Huang
Keyword(s):  
Hausdorff Measure ◽  
General Class ◽  
Measure Theory ◽  
Complete Theory ◽  
Planar Curves ◽  
The Subject ◽  
Hausdorff Theory ◽  
Challenging Question

AbstractTen years ago, Beresnevich–Dickinson–Velani [Mem. Amer. Math. Soc. 179 (2006), no. 846] initiated a project that develops the general Hausdorff measure theory of dual approximation on non-degenerate manifolds. In particular, they established the divergence part of the theory based on their general ubiquity framework. However, the convergence counterpart of the project remains wide open and represents a major challenging question in the subject. Until recently, it was not even known for any single non-degenerate manifold. In this paper, we settle this problem for all curves in{\mathbb{R}^{2}}, which represents the first complete theory of its kind for a general class of manifolds.

Asymptotics for Minimal Discrete Riesz Energy on Curves in ℝd

2004 ◽  
Vol 56 (3) ◽  
pp. 529-552 ◽  
Author(s):  
A. Martínez-Finkelshtein ◽  
V. Maymeskul ◽  
E. A. Rakhmanov ◽  
E. B. Saff
Keyword(s):  
Jordan Curve ◽  
Hausdorff Measure ◽  
Compact Sets ◽  
Minimizing Sequences ◽  
Point Sets ◽  
Dimensional Hausdorff Measure ◽  
One Dimensional ◽  
Riesz Kernel ◽  
Riesz Energy ◽  
Image Position

AbstractWe consider the s-energy for point sets 𝒵 = {𝒵k,n: k = 0, …, n} on certain compact sets Γ in ℝd having finite one-dimensional Hausdorff measure,is the Riesz kernel. Asymptotics for the minimum s-energy and the distribution of minimizing sequences of points is studied. In particular, we prove that, for s ≥ 1, the minimizing nodes for a rectifiable Jordan curve Γ distribute asymptotically uniformly with respect to arclength as n → ∞.

scholarly journals Formulation of scale transformation in a stochastic data assimilation framework

2017 ◽  
Vol 24 (2) ◽  
pp. 279-291 ◽  
Author(s):  
Feng Liu ◽  
Xin Li
Keyword(s):  
Data Assimilation ◽  
Spatial Scale ◽  
Measure Theory ◽  
Stochastic Calculus ◽  
Scale Transformation ◽  
Earth Observations ◽  
Model Unit ◽  
Stochastic Data ◽  
Definition Of ◽  
New Formulation

Abstract. Understanding the errors caused by spatial-scale transformation in Earth observations and simulations requires a rigorous definition of scale. These errors are also an important component of representativeness errors in data assimilation. Several relevant studies have been conducted, but the theory of the scale associated with representativeness errors is still not well developed. We addressed these problems by reformulating the data assimilation framework using measure theory and stochastic calculus. First, measure theory is used to propose that the spatial scale is a Lebesgue measure with respect to the observation footprint or model unit, and the Lebesgue integration by substitution is used to describe the scale transformation. Second, a scale-dependent geophysical variable is defined to consider the heterogeneities and dynamic processes. Finally, the structures of the scale-dependent errors are studied in the Bayesian framework of data assimilation based on stochastic calculus. All the results were presented on the condition that the scale is one-dimensional, and the variations in these errors depend on the differences between scales. This new formulation provides a more general framework to understand the representativeness error in a non-linear and stochastic sense and is a promising way to address the spatial-scale issue.

Dimensions of measures under orthogonal projections

1996 ◽  
Vol 28 (2) ◽  
pp. 344-345
Author(s):  
Martina Zähle
Keyword(s):  
Hausdorff Dimension ◽  
Packing Dimension ◽  
Packing Measure ◽  
Orthogonal Projections

Let dimH, E be the Hausdorff dimension and dimP, E the packing dimension of the subset E of ℝn given by the unique exponent where the corresponding Hausdorff or packing measure of E jumps from infinity to zero.

scholarly journals Packing dimension and measure of homogeneous Cantor sets

2006 ◽  
Vol 74 (3) ◽  
pp. 443-448 ◽  
Author(s):  
H.K. Baek
Keyword(s):  
Lower Bound ◽  
Explicit Formula ◽  
Cantor Sets ◽  
Packing Dimension ◽  
Packing Measure ◽  
Hausdorff Measures ◽  
Packing Dimensions

For a class of homogeneous Cantor sets, we find an explicit formula for their packing dimensions. We then turn our attention to the value of packing measures. The exact value of packing measure for homogeneous Cantor sets has not yet been calculated even though that of Hausdorff measures was evaluated by Qu, Rao and Su in (2001). We give a reasonable lower bound for the packing measures of homogeneous Cantor sets. Our results indicate that duality does not hold between Hausdorff and packing measures.

Analytic sets from the point of view of compact sets

1986 ◽  
Vol 99 (1) ◽  
pp. 1-4
Author(s):  
Howard Becker
Keyword(s):  
Point Of View ◽  
Compact Sets ◽  
Analytic Sets

A set A ⊂ ωω is called compactly if, for every compact K ⊂ ωω, A ∩ K is . Consider the proposition that every compactly set is . (AD implies that it is true, ZFC + CH implies that it is false.) We are concerned here with whether this is consistent with ZFC, particularly when n = 1. In the case of sets (that is, analytic sets), this consistency question is due to Fremlin (see [7], page 483, problem 18). Kunen and Miller [3] have proved the following two theorems.

Topological differential fields and dimension functions

2012 ◽  
Vol 77 (4) ◽  
pp. 1147-1164 ◽  
Author(s):  
Nicolas Guzy ◽  
Françoise Point
Keyword(s):  
Dimension Function ◽  
Dimension Functions ◽  
Differential Fields

AbstractWe construct a fibered dimension function in some topological differential fields.

scholarly journals Small sets containing any pattern

2018 ◽  
Vol 168 (1) ◽  
pp. 57-73
Author(s):  
URSULA MOLTER ◽  
ALEXIA YAVICOLI
Keyword(s):  
Hausdorff Measure ◽  
Analogous Result ◽  
Measure Zero ◽  
General Construction ◽  
Dimension Function ◽  
Perfect Set ◽  
Finite Set ◽  
Isolated Points ◽  
Special Case

AbstractGiven any dimension function h, we construct a perfect set E ⊆ ${\mathbb{R}}$ 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 have a family of functions $\mathcal{F}$ that satisfy certain conditions and we construct a perfect set E in ${\mathbb{R}}^N$, of h-Hausdorff measure zero, such that for any finite set {f1,. . .,fn} ⊆ $\mathcal{F}$, E satisfies that $\bigcap_{i=1}^n f^{-1}_i(E)\neq\emptyset$.We also obtain an analogous result for the images of functions. Additionally we prove some related results for countable (not necessarily finite) intersections, obtaining, instead of a perfect set, an $\mathcal{F}_{\sigma}$ set without isolated points.

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