Abstract:
In § 1 the improvement of the estimates on the Hausdorff and fractal dimensions of a bounded semi-invariant subset in a Hilbert space is given. In § 2 my previous results, concerning the semigroups with a continuous group parameter $t\in\mathrm{R}^+=[0,\infty)$, are extended to the case where $t$ varies in a semigroup $\mathcal{J}^+=\{t\in\mathcal{J}\mid t\geqslant0\}$ of positive elements of some additive group $\mathcal{J}\subset\mathrm{R}=(-\infty,\infty)$.