Approximation by quasi-projection operators and dual wavelet frames in Sobolev spaces

Danila Kotov, Aleksandr Krivoshein

For a quasi-projection operator $Q_j(f,\ddot{I}•,\tilde{\ddot{I}}•)$ formed by a compactly supported function $\ddot{I}•$ and a compactly supported distribution $\tilde{\ddot{I}}•$ with dilation matrix $…