Book ChapterDOI
Wiener’s Lemma: Theme and Variations. An Introduction to Spectral Invariance and Its Applications
Karlheinz Gröchenig
- pp 175-234
TLDR
It is proved Wiener’s Lemma is proved and equivalent formulations about convolution operators are discussed and the underlying abstract concepts from Banach algebras are extracted.Abstract:
Wiener’s Lemma is a classical statement about absolutely convergent Fourier series and remains one of the driving forces in the development of Banach algebra theory. In the first part of the chapter—the theme—we discuss Wiener’s Lemma in detail. We prove Wiener’s Lemma and discuss equivalent formulations about convolution operators.We then extract the underlying abstract concepts from Banach algebras. In the second part of the chapter—the variations—we discuss several, mostly noncommutative reincarnations of Wiener’s Lemma. We will develop some of the theoretical background and explain why Wiener’s Lemma is still useful and inspiring. The topics cover weighted versions of Wiener’s Lemma, infinite matrix algebras, noncommutative tori and time-frequency analysis, convolution operators on noncommutative groups, and time-varying systems and pseudodifferential operators.read more
Citations
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Journal ArticleDOI
Wiener algebras of Fourier integral operators
TL;DR: In this article, a one-parameter family of algebras FIO ( Ξ, s ), 0 ⩽ s⩽ ∞, consisting of Fourier integral operators is constructed, which is defined by the decay properties of an associated Gabor matrix around the graph of the canonical transformation.
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Generalized Metaplectic Operators and the Schr\"odinger Equation with a Potential in the Sj\"ostrand Class
TL;DR: In this paper, it was shown that the one-parameter group generated by a Hamiltonian operator with a potential in the Sjostrand class consists of generalized metaplectic operators.
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Noncommutative Approximation: Inverse-Closed Subalgebras and Off-Diagonal Decay of Matrices
TL;DR: In this paper, the authors investigated two systematic constructions of inverse-closed subalgebras of a given Banach algebra or operator algebra, both of which are inspired by classical principles of approximation theory.
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Decay properties for functions of matrices over C⁎-algebras
Michele Benzi,Paola Boito +1 more
TL;DR: In this article, the authors extend previous results on the exponential off-diagonal decay of the entries of analytic functions of banded and sparse matrices to the case where the matrix entries are elements of a C ⁎ -algebra.
Journal ArticleDOI
Generalized metaplectic operators and the Schrödinger equation with a potential in the Sjöstrand class
TL;DR: In this paper, it was shown that the one-parameter group generated by a Hamiltonian operator with a potential in the Sjostrand class consists of generalized metaplectic operators.