A Note on Fractal Measures and Cartesian Product Sets

Autor: Meriem Ben Hadj Khlifa, Najmeddine Attia, Hajer Jebali
Rok vydání: 2021
Předmět:
Zdroj: Bulletin of the Malaysian Mathematical Sciences Society. 44:4383-4404
ISSN: 2180-4206
0126-6705
DOI: 10.1007/s40840-021-01172-1
Popis: In this paper, we give a new product formula : $$\begin{aligned} {\mathsf {H}}^t(E) {\mathsf {H}}^s(F)\le c_1 {\mathsf {H}}^{t+s}(E\times F)\le & {} c_2 {\mathsf {H}}^s(E) {\mathsf {P}}^t(F)\\\le & {} c_3 {\mathsf {P}}^{t+s}(E\times F) \le c_4 {\mathsf {P}}^s(E) {\mathsf {P}}^t(F). \end{aligned}$$ where $$E\subseteq \mathbb {R}^d$$ , $$F\subseteq \mathbb {R}^l$$ , $$t,s\ge 0$$ and $$ {\mathsf {H}}^t$$ and $${\mathsf {P}}^s$$ denote, respectively, the lower and upper Hewitt–Stromberg measures. Using these inequalities, we give lower and upper bounds for the lower and upper Hewitt–Stromberg dimensions $${\mathsf {b}}(E\times F)$$ and $${\mathsf {B}}(E\times F)$$ in terms of the Hewitt–Strombeg dimensions of E and F.
Databáze: OpenAIRE