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

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Suppose $G$ is a second countable, locally compact Hausdorff groupoid with abelian stabilizer subgroups and a Haar system. We provide necessary and sufficient conditions for the groupoid $C^*$-algebra to have Hausdorff spectrum. In…

Operator Algebras · Mathematics 2012-07-31 Geoff Goehle

In this paper we construct frames of Gabor type for the space $L^2_{rad}(\R^d)$ of radial $L^2$-functions, and more generally, for subspaces of modulation spaces consisting of radial distributions. Hereby, each frame element itself is a…

Functional Analysis · Mathematics 2016-09-07 Holger Rauhut

We propose the general scheme of incorporation of the Dirac monopoles into mechanical systems on the three-dimensional conformal flat space. We found that any system (without monopoles) admitting the separation of variables in the elliptic…

High Energy Physics - Theory · Physics 2008-11-26 Sergey Krivonos , Armen Nersessian , Vadim Ohanyan

The image of a given orthonormal basis for a separable Hilbert space $\mathcal{H}$ under a bijective, bounded, and linear operator acting on $\mathcal{H}$ is called a Riesz basis of $\mathcal{H}$. Contrary to what happens with Riesz bases…

Functional Analysis · Mathematics 2026-01-27 Jyoti , Lalit Kumar Vashisht

We propose and analyze a robust BPX preconditioner for the integral fractional Laplacian on bounded Lipschitz domains. For either quasi-uniform grids or graded bisection grids, we show that the condition numbers of the resulting systems…

Numerical Analysis · Mathematics 2021-06-04 Juan Pablo Borthagaray , Ricardo H. Nochetto , Shuonan Wu , Jinchao Xu

In this paper, first we revisit the formal integration of Lie algebras, which give rise to braces in some special cases. Then we establish the formal integration theory for complete Rota-Baxter Lie algebras, that is, we show that there is a…

Mathematical Physics · Physics 2026-02-12 Maxim Goncharov , Pavel Kolesnikov , Yunhe Sheng , Rong Tang

The dual action of a locally compact abelian group, in the context of C*-algebraic bundles, is shown to satisfy an integrability property, similar to Rieffel's proper actions. The tools developed include a generalization of Bochner's…

funct-an · Mathematics 2008-02-03 Ruy Exel

We study the bounded endomorphisms of $\ell_{N}^2(G)=\ell^2(G)\times \dots \times\ell^2(G)$ that commute with translations, where $G$ is a discrete abelian group. It is shown that they form a C*-algebra isomorphic to the C*-algebra of…

Functional Analysis · Mathematics 2019-04-25 Gerardo Perez-Villalon

Motivated by Bownik and Speegle's result on linear independence of wavelet Parseval frames, we consider affine systems (analogous to wavelet systems) defined on a second countable, locally compact abelian group $G$, where the translations…

Functional Analysis · Mathematics 2016-08-31 Sandra Saliani

We discuss necessary as well as sufficient conditions for the second iterated local multiplier algebra of a separable C*-algebra to agree with the first.

Operator Algebras · Mathematics 2014-02-26 Pere Ara , Martin Mathieu

The usefulness of Gabor frames depends on the easy computability of a suitable dual window. This question is addressed under several aspects: several versions of Schulz's iterative algorithm for the approximation of the canonical dual…

Numerical Analysis · Mathematics 2015-06-24 Tobias Kloos , Joachim Stöckler , Karlheinz Gröchenig

We consider translates of functions in $L^2(\RRd)$ along an irregular set of points. Introducing a notion of pseudo-Gramian function for the irregular case, we obtain conditions for a family of irregular translates to be a Bessel sequence…

Classical Analysis and ODEs · Mathematics 2014-07-17 Peter Balazs , Sigrid Heineken

We prove well-posedness of the analytic Cauchy problem for gradient generalized Ricci solitons on an abelian bundle gerbe and solve the initial data equations on every compact Riemann surface. Along the way, we provide a novel…

Differential Geometry · Mathematics 2026-04-27 Severin Bunk , Miguel Pino Carmona , C. S. Shahbazi

Let G be a nonlinear double cover of the real points of a connected reductive complex algebraic group with simply laced root system. We establish a uniform character multiplicity duality theory for the category of Harish-Chandra modules for…

Representation Theory · Mathematics 2019-02-20 Jeffrey Adams , Peter E. Trapa

Suppose that G is an abelian group, A is a finite subset of G with |A+A|< K|A| and eta in (0,1] is a parameter. Our main result is that there is a set L such that |A cap Span(L)| > K^{-O_eta(1)}|A| and |L| = O(K^eta log |A|). We include an…

Classical Analysis and ODEs · Mathematics 2018-11-05 Tom Sanders

Let $G$ be an LCA group, $H$ a closed subgroup, $\varGamma$ the dual group of $G$. In accordance with analogous notions in prediction theory the classes of $H$-regular and $H$-singular Borel measures on $\Gamma$ are defined. A…

Functional Analysis · Mathematics 2017-09-12 Lutz Peter Klotz , Juan Miguel Medina

The class of locally compact near abelian groups is introduced and investigated as a class of metabelian groups formalizing and applying the concept of scalar multiplication. The structure of locally compact near abelian groups and its…

Group Theory · Mathematics 2017-02-14 Karl H. Hofmann , Wolfgang Herfort , Francesco G. Russo

We investigate the automatic regularity of bounded derivations from a Banach lattice algebra of regular operators A into a Banach A-module with a Banach lattice structure compatible with the module operations.

Functional Analysis · Mathematics 2022-06-22 Ariel Blanco

In this paper we study the Riesz transform on complete and connected Riemannian manifolds $M$ with a certain spectral gap in the $L^2$ spectrum of the Laplacian. We show that on such manifolds the Riesz transform is $L^p$ bounded for all $p…

Spectral Theory · Mathematics 2010-05-18 Lizhen Ji , Peer Kunstmann , Andreas Weber

Using a variant of the Sobolev Embedding Theorem, we prove an uncertainty principle related to Gabor systems that generalizes the Balian-Low Theorem. Namely, if $f\in H^{p/2}(\R)$ and $\hat f\in H^{p'/2}(\R)$ with $1<p<\infty$,…

Classical Analysis and ODEs · Mathematics 2010-07-16 S. Zubin Gautam