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Related papers: A Hilbert C*-module for Gabor systems

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We show that for an arbitrary totally positive function $g\in L^1(\mathbb{R} )$ and $\alpha \beta$ rational, the Gabor family $\{e^{2\pi i \beta l t} g(t-\alpha k): k,l \in \mathbb{Z} \}$ is a frame for $L^2(\mathbb{R})$, if and only if…

Functional Analysis · Mathematics 2024-05-21 Karlheinz Gröchenig

Let $A$ be a (non-unital, in general) C*-algebra with center $Z(M(A))$ of its multiplier algebra, and let $\{ X, \langle .,. \rangle \}$ be a full Hilbert $A$-module. Then any bijective bounded module morphism $T$, for which every…

Operator Algebras · Mathematics 2026-04-09 Michael Frank

Motivated by a general dilation theory for operator-valued measures, framings and bounded linear maps on operator algebras, we consider the dilation theory of the above objects with special structures. We show that every operator-valued…

Functional Analysis · Mathematics 2014-11-18 Deguang Han , David R. Larson , Bei Liu , Rui Liu

The algebraic structure of moduli spaces of 3d N=2 supersymmetric gauge theories is studied by computing the Hilbert series which is a generating function that counts gauge invariant operators in the chiral ring. These U(N_c) theories with…

High Energy Physics - Theory · Physics 2015-11-24 Amihay Hanany , Chiung Hwang , Hyungchul Kim , Jaemo Park , Rak-Kyeong Seong

In this paper, firstly we investigate conditions under which the action of an operator on a $K$-frame, remain again a $K$-frame for Hilbert module E. We also give a generalization of Douglas Theorem and we shall use it to prove the sum of…

Operator Algebras · Mathematics 2018-02-07 Gh. Abbaspour Tabadkan , A. A. Arefijamaal , M. Mahmoudieh

Frame multipliers are an abstract version of Toeplitz operators in frame theory and consist of a composition of a multiplication operator with the analysis and synthesis operators. Whereas the boundedness properties of frame multipliers on…

Functional Analysis · Mathematics 2025-06-24 Peter Balazs , Karlheinz Gröchenig

We introduce the notion of Hilbert $C^*$-module independence: Let $\mathscr{A}$ be a unital $C^*$-algebra and let $\mathscr{E}_i\subseteq \mathscr{E},\,\,i=1, 2$, be ternary subspaces of a Hilbert $\mathscr{A}$-module $\mathscr{E}$. Then…

Operator Algebras · Mathematics 2021-04-20 R. Eskandari , J. Hamhalter , M. S. Moslehian , V. M. Manuilov

We present a short and elegant proof of the complete theory of strict representations of the algebra B^a(E) of all adjointable operators on a Hilbert B-module E by operators on a Hilbert C-module F. Aanalogue for W*-modules and normal…

Operator Algebras · Mathematics 2007-05-23 P. S. Muhly , M. Skeide , B. Solel

In this paper, we will introduce the new concepts of continuous bi-g-frames and continuous K-bi-g-frame for Hilbert spaces. Then, we examine some characterizations properties with the help of a biframe operator. Finally, we investigate…

Functional Analysis · Mathematics 2024-04-16 Abdelilah Karara , Mohamed Rossafi

After recalling in detail some basic definitions on Hilbert C*-bimodules, Morita equivalence and imprimitivity, we discuss a spectral reconstruction theorem for imprimitivity Hilbert C*-bimodules over commutative unital C*-algebras and…

Operator Algebras · Mathematics 2008-12-19 Paolo Bertozzini , Roberto Conti , Wicharn Lewkeeratiyutkul

In previous work, we defined and studied $\Sigma^*$-modules, a class of Hilbert $C^*$-modules over $\Sigma^*$-algebras (the latter are $C^*$-algebras that are sequentially closed in the weak operator topology). The present work continues…

Operator Algebras · Mathematics 2019-01-31 Clifford A. Bearden

In this paper we survey our recent work on C*-correspondences and their associated operator algebras; in particular, on adding tails, the Shift Equivalence Problem and Hilbert bimodules.

Operator Algebras · Mathematics 2014-04-08 Evgenios T. A. Kakariadis , Elias G. Katsoulis

Given a correspondence X over a C*-algebra A, we construct a C*-algebra and a Hilbert C*-bimodule over it whose crossed product is isomorphic to the augmented Cuntz-Pimsner C*-algebra of X. This construction enables us to establish a…

Operator Algebras · Mathematics 2007-05-23 Beatriz Abadie , Mauricio Achigar

We initiate the study of computable presentations of real and complex C*-algebras under the program of effective metric structure theory. With the group situation as a model, we develop corresponding notions of recursive presentations and…

Logic · Mathematics 2023-04-17 Alec Fox

The frame set of a function $g\in L^2(\mathbb{R})$ is the subset of all parameters $(a, b)\in \mathbb{R}^2_+$ for which the time-frequency shifts of $g$ along $a\mathbb{Z}\times b\mathbb{Z}$ form a Gabor frame for $L^2(\mathbb{R}).$ In this…

Functional Analysis · Mathematics 2018-06-05 A. Ganiou D. Atindehou , Yebeni B. Kouagou , Kasso A. Okoudjou

We show that, when $A$ is a separable C*-algebra, every countably generated Hilbert $A$-module is projective (with bounded module maps as morphisms). We also study the approximate extensions of bounded module maps. In the case that $A$ is a…

Operator Algebras · Mathematics 2023-01-12 Lawrence G. Brown , Huaxin Lin

A Banach involutive algebra is called a Krein C*-algebra if there is a fundamental symmetry (an involutive automorphism of period 2) such that the C*-property is satisfied when the original involution is replaced with the new one obtained…

Operator Algebras · Mathematics 2014-09-05 Pichkitti Bannangkoon , Paolo Bertozzini , Wicharn Lewkeeratiyutkul

Let $A$ be a Banach algebra. By $\sigma(x)$ and $r(x)$ we denote the spectrum and the spectral radius of $x\in A$, respectively. We consider the relationship between elements $a,b\in A$ that satisfy one of the following two conditions: (1)…

Operator Algebras · Mathematics 2012-04-24 M. Brešar , Š. Špenko

For a class of compactly supported windows we characterize the frame property for a Gabor system $\mts,$ for translation parameters $a$ belonging to a certain range depending on the support size. We show that the obstructions to the frame…

Functional Analysis · Mathematics 2015-03-10 Ole Christensen , Hong Oh Kim , Rae Young Kim

Suppose $A$ is a pro-C*-algebra. Let $L_{A}(E)$ be the pro-C*-algebra of adjointable operators on a Hilbert $A$-module $E$ and let $K_{A}(E)$ be the closed two sided $*$-ideal of all compact operators on $E$. We prove that if $E$ be a full…

Operator Algebras · Mathematics 2016-12-13 Khadijeh Karimi , Kamran Sharifi
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