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Related papers: On Riesz duals for the Gabor system on LCA groups

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Gabor frames have gained considerable popularity during the past decade, primarily due to their substantiated applications in diverse and widespread fields of engineering and science. Finding general and verifiable conditions which imply…

Functional Analysis · Mathematics 2016-10-31 Firdous A. Shah

We show that if the Gabor system $\{ g(x-t) e^{2\pi i s x}\}$, $t \in T$, $s \in S$, is an orthonormal basis in $L^2(\mathbb{R})$ and if the window function $g$ is compactly supported, then both the time shift set $T$ and the frequency…

Classical Analysis and ODEs · Mathematics 2025-01-10 Alberto Debernardi Pinos , Nir Lev

In this article, we discuss subspace duals of a frame of translates by an action of a closed abelian subgroup $\Gamma$ of a locally compact group $\mathscr G.$ These subspace duals are not required to lie in the space generated by the…

Functional Analysis · Mathematics 2023-09-19 Sudipta Sarka , Niraj K. Shukla

We extend the Balian-Low theorem to Gabor subspaces of $L^2(\mathbb R)$ by involving the concept of additional time-frequency shift invariance. We prove that if a Gabor system on a lattice of rational density is a Riesz sequence generating…

Functional Analysis · Mathematics 2018-06-14 A. Caragea , D. Lee , G. E. Pfander , F. Philipp

The topic of this paper are (multi-window) Gabor frames for signals over finite Abelian groups, generated by an arbitrary lattice within the finite time-frequency plane. Our generic approach covers simultaneously multi-dimensional signals…

Group Theory · Mathematics 2008-03-17 H. G. Feichtinger , W. Kozek , F. Luef

Let $G$ be a second-countable amenable group with a uniform $k$-approximate lattice $\Lambda$. For a projective discrete series representation $(\pi, \mathcal{H}_{\pi})$ of $G$ of formal degree $d_{\pi} > 0$, we show that $D^-(\Lambda) \geq…

Functional Analysis · Mathematics 2023-10-05 Ulrik Enstad , Jordy Timo van Velthoven

v2: An additional assumption was added in Theorem 4.8. In order to show that a connected abelian group is admissible on the site of locally compact spaces we must in addition assume that it is locally topologically divisible. This condition…

Algebraic Topology · Mathematics 2018-11-28 Ulrich Bunke , Thomas Schick , Markus Spitzweck , Andreas Thom

We show that the construction of Gabor frames in $L^{2}(\mathbb{R})$ with generators in $\mathbf{S}_{0}(\mathbb{R})$ and with respect to time-frequency shifts from a rectangular lattice $\alpha\mathbb{Z}\times\beta\mathbb{Z}$ is equivalent…

Functional Analysis · Mathematics 2022-10-21 Ulrik B. R. Enstad , Mads S. Jakobsen , Franz Luef

We give a construction of Gabor type frames for suitable separable subspaces of the non-separable Hilbert spaces $AP_2({\mathbb R})$ of almost periodic functions of one variable. Furthermore we determine a non-countable generalized frame…

Functional Analysis · Mathematics 2014-12-12 Paolo Boggiatto , Carmen Fernández , Antonio Galbis

The duality principle for group representations developed in \cite{DHL-JFA, HL_BLM} exhibits a fact that the well-known duality principle in Gabor analysis is not an isolated incident but a more general phenomenon residing in the context of…

Functional Analysis · Mathematics 2018-12-10 Radu Balan , Dorin Ervin Dutkay , Deguang Han , David Larson , Franz Luef

We construct Hilbert $C^*$-modules useful for studying Gabor systems and show that they are Banach algebras under pointwise multiplication. For rational $ab<1$ we prove that the set of functions $g \in L^2(R)$ so that $(g,a,b)$ is a Bessel…

Functional Analysis · Mathematics 2007-05-23 Michael Coco , M. C. Lammers

We generalize Feichtinger and Kaiblinger's theorem on linear deformations of uniform Gabor frames to the setting of a locally compact abelian group $G$. More precisely, we show that Gabor frames over lattices in the time-frequency plane of…

Functional Analysis · Mathematics 2022-10-21 Ulrik Enstad , Mads S. Jakobsen , Franz Luef , Tron Omland

We investigate the class of root systems $R$ obtained by extending an $A_1$-type irreducible root system by a free abelian group $G$. In this context there is a Weyl group $W$ and a group $U$ with the presentation by conjugation. Both…

Group Theory · Mathematics 2008-04-11 Georg W. Hofmann

We investigate the completeness of Gabor systems with respect to several classes of window functions on rational lattices. Our main results show that the time-frequency shifts of every finite linear combination of Hermite functions with…

Mathematical Physics · Physics 2016-11-29 Karlheinz Gröchenig , Antti Haimi , José Luis Romero

Given a locally compact abelian group $G$ and a closed subgroup $\Lambda$ in $G\times\widehat{G}$, Rieffel associated to $\Lambda$ a Hilbert $C^*$-module $\mathcal{E}$, known as a Heisenberg module. He proved that $\mathcal{E}$ is an…

Functional Analysis · Mathematics 2020-09-08 Mads S. Jakobsen , Franz Luef

This paper discusses sufficient conditions for a definably complete densely linearly ordered expansion of an abelian group having the uniformly locally o-minimal open cores of the first/second kind and strongly locally o-minimal open core,…

Logic · Mathematics 2022-06-08 Masato Fujita

We provide a necessary and sufficient condition to ensure that a multi-tile $\Omega$ of $R^d$ of positive measure (but not necessarily bounded) admits a structured Riesz basis of exponentials for $ L^{2}(\Omega )$. New examples are given…

Classical Analysis and ODEs · Mathematics 2020-02-03 Carlos Cabrelli , Kathryn Hare , Ursula Molter

Given a window $\phi \in L^2(\mathbb R),$ and lattice parameters $\alpha, \beta>0,$ we introduce a bimodal Wilson system $\mathcal{W}(\phi, \alpha, \beta)$ consisting of linear combinations of at most two elements from an associated Gabor…

Functional Analysis · Mathematics 2018-12-20 Divyang G. Bhimani , Kasso A. Okoudjou

Given a locally compact group bundle, we show that the system of the Plancherel weights of their C*-algebras is lower semi-continuous. As a corollary, we obtain that the dual Haar sytem of a continuous Haar system of a locally compact…

Operator Algebras · Mathematics 2020-11-25 Jean Renault

We examine sufficient conditions for the dual of a topological group to be metrizable and locally compact.

General Topology · Mathematics 2016-03-01 Frédéric Mynard , Mikhail Tkachenko