We establish dilation theorems for non-tight frames with additional structure, i.e., frames generated by unitary groups of operators and projective unitary representations. This generalizes previous dilation results for Parseval frames due to Han and Larson [6] and Gabardo and Han [5]. We also extend the dilation theorem for Parseval wavelets, due to Dutkay, Han, Picioroaga, and Sun [4], by ide...

In this paper, we establish the asymptotic estimates for norms of matrix dilation operators on modulation spaces. As an application, study boundedness spaces Hausdorff operators. The definition are also revisited fitting our study.

We consider dilation operators Tk : f → f(2·) in the framework of Besov spaces B p,q(R ) when 0 < p ≤ 1. If s > n ` 1 p − 1 ́ , Tk is a bounded linear operator from B p,q(R ) into itself and there are optimal bounds for its norm. We study the situation on the line s = n `