Skip to main content

All Questions

12 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
11 votes
0 answers
337 views

Hausdorff dimension and von Neumann dimension

There are two subjects in which non-integral dimensions appear: fractal geometry: consider the well-known Hausdorff dimension of fractals. von Neumann algebra: consider a type ${\rm II_1}$ ...
Sebastien Palcoux's user avatar
5 votes
0 answers
160 views

Naïve definition of a measure on a fractal

This question was previously posted on MSE. Let $K\subset \mathbb R^2$ be a compact fractal of Hausdorff dimension $1<d<2$. I want to define a natural measure on $K$. One option would be to use ...
Matheus Manzatto's user avatar
4 votes
0 answers
79 views

An algebraic condition possibly related with the Hausdorff measure on $\mathbb{R}$

This is my first time to ask a question here. Please tell me if I can improve it. I would like to introduce the following definition inspired from a measure theory exercise. Definition. A subset $K$ ...
Jianqiao Shang's user avatar
4 votes
0 answers
95 views

Counting fractals modulo "shared complements"

Previously asked at MSE: Let $\mathscr{H}$ be the space of compact nonempty subsets of $\mathbb{R}^2$ (I'm not especially wedded to dimension $2$, so feel free to tweak that if it would lead to a more ...
Noah Schweber's user avatar
3 votes
1 answer
105 views

Existence of an $\alpha$-regular measure with positive measure on a binary digits do not have a limiting frequency

let $$X=\left\{ \sum_{n=1}^{\infty}a_{n}2^{-n}:a_{n}\in\left\{ 0,1\right\} ,\liminf\frac{1}{n}\sum_{i=1}^{n}a_{i}<\limsup\frac{1}{n}\sum_{i=1}^{n}a_{i}\right\} $$ I'm studying fractal geometry and ...
Simple Conjugate's user avatar
3 votes
0 answers
204 views

Product Fractals

Here is a theorem found in the Falconer's book on fractal geometry: Theorem: For any sets $E\subset \mathbb{R}^n$ and $F\subset \mathbb{R}^m$ $$ \dim_HF+\dim_HE\leq \dim_H(E\times F)\leq \dim_HE+\...
user avatar
2 votes
0 answers
99 views

Hausdorff dimension between $(1,2)$

Is there a number $c \in (1,2)$ for which there exist some interesting geometric property/properties which hold for every set of Hausdorff dimension in $(1,c)$ and does not hold for any set of ...
truebaran's user avatar
  • 9,340
2 votes
0 answers
85 views

Intersections of Sierpinski carpets with lines

Let $S$ be the Sierpinski carpet contained in the square $[0,1]^2$. For Lebesgue almost every $a\in [0,1]^2$ and every $\theta\in\mathbb Q$ the intersection of the line $L_{a,\theta}$ with equation $y-...
DavidHume's user avatar
  • 743
1 vote
0 answers
27 views

What is $3/2$-dimensional Hausdorff measure of the graph of Brownian motion?

It is well-known, and well-documented, that the Hausdorff dimension of the graph of regular $1$-dimensional Brownian motion is $3/2$ (almost surely). See for example Theorem 4.29 in "Brownian ...
mdr's user avatar
  • 583
1 vote
0 answers
114 views

density of fractal measures

Let $s\in (0, 1)$ be a real number. Let $E\subset [0, 1]$ be a Borel set whose Hausdorff dimension is given by $s$. Assume that $\mathcal{H}^s(E)=+\infty$, that is, the $s$-dimensional Hausdorff ...
Guo's user avatar
  • 11
0 votes
0 answers
151 views

Set with modified lower box counting dimension strictly less than Hausdorff dimension

Please, can someone give (as simple as possible) example of the set for which modified lower box counting dimension is strictly smaller than Hausdorff dimension?
Dopax's user avatar
  • 1
0 votes
0 answers
122 views

Hausdorff dimension of $X\times X$

I am thinking of the following question: Let $X\subseteq \mathbb R$. Is it true that $$ \mathrm{dim_H}(X\times X)=2\mathrm{dim_H}(X)? $$ My thoughts: We know that $\mathrm{dim_H}(X)+\mathrm{dim_H}(...
Thomas Yang's user avatar