Mean dimension and an embedding theorem for real flows
Tom 251 / 2020
Streszczenie
We develop mean dimension theory for $\mathbb {R}$-flows. We obtain fundamental properties and examples and prove an embedding theorem: Any real flow $(X,\mathbb {R})$ of mean dimension strictly less than $r$ admits an extension $(Y,\mathbb {R})$ whose mean dimension is equal to that of $(X,\mathbb {R})$ and such that $(Y,\mathbb {R})$ can be embedded in the $\mathbb {R}$-shift on the compact function space $\{f\in C(\mathbb {R},[-1,1]) : \operatorname{supp} (\hat {f})\subset [-r,r]\}$, where $\hat {f}$ is the Fourier transform of $f$ considered as a tempered distribution. These canonical embedding spaces appeared previously as a tool in embedding results for $\mathbb {Z}$-actions.