Biorthogonal Wavelets on the Spectrum

TL;DR

This paper extends multiresolution analysis theory to biorthogonal nonuniform wavelets on spectral sets, providing conditions for Riesz bases and biorthogonality, advancing wavelet theory on nonuniform spectra.

Contribution

It introduces biorthogonal nonuniform multiresolution analysis on spectral sets and characterizes biorthogonality and Riesz basis conditions for associated wavelets.

Findings

Established necessary and sufficient conditions for Riesz bases.

Provided complete characterization of biorthogonality of wavelet translates.

Showed wavelets can generate Riesz bases under mild assumptions.

Abstract

A generalization of Mallat's classic theory of multiresolution analysis based on the theory of spectral pairs was considered by Gabardo and Nashed (J. Funct. Anal. 158, 209-241, 1998). In this article, we introduce the notion of biorthgonoal nonuniform multiresolution analysis on the spectrum $\Lambda=\left\{0, r/N\right\}+2\mathbb Z$, where $N\ge 1$ is an integer and $r$ is an odd integer with $1\le r\le 2N-1$ such that $r$ and $N$ are relatively prime. We first establish the necessary and sufficient conditions for the translates of a single function to form the Riesz bases for their closed linear span. We provide the complete characterization for the biorthogonality of the translates of scaling functions of two nonuniform multiresolution analysis and the associated biorthogonal wavelet families. Furthermore, under the mild assumptions on the scaling functions and the corresponding wavelets associated with nonuniform multiresolution analysis, we show that the wavelets can generate Reisz bases.