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Related papers: Continuous Riesz bases in Hilbert C*-modules

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Halmos' two projections theorem for Hilbert space operators is one of the fundamental results in operator theory. In this paper, we introduce the term of two harmonious projections in the context of adjointable operators on Hilbert…

Functional Analysis · Mathematics 2021-07-23 Wei Luo , Mohammad Sal Moslehian , Qingxiang Xu

Different (fibrewise) amalgamated products of continuous C*-bundles have been studied over the last years, one of the main question being to know when these amalgamated products are continuous C*-bundles. In order to gather these approaches…

Operator Algebras · Mathematics 2008-03-03 Etienne Blanchard

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

A $\Sigma^*$-algebra is a concrete $C^*$-algebra that is sequentially closed in the weak operator topology. We study an appropriate class of $C^*$-modules over $\Sigma^*$-algebras analogous to the class of $W^*$-modules (selfdual…

Operator Algebras · Mathematics 2016-09-13 Clifford A. Bearden

Rigged modules over an operator algebra are a generalization of Hilbert modules over a $C^{\star}$-algebra. We characterize the rigged modules over an operator algebra $\mathcal A$ which are orthogonally complemented in $C_\infty(\mathcal…

Operator Algebras · Mathematics 2021-09-01 G. K. Eleftherakis , E. Papapetros

In this paper, we prove that a sequence of generalized eigenvectors of a linear unbounded operator associated with an Euler-Bernoulli beam equation under bending moment boundary feedback forms a Riesz basis for the underlying state Hilbert…

Optimization and Control · Mathematics 2017-05-12 Hua-Cheng Zhou

Frame Theory has a great revolution for recent years. This theory has been extended from Hilbert spaces to Hilbert $C^{\ast}$-modules. In this paper, we introduce the concept of Controlled K-operator frame for the space…

Functional Analysis · Mathematics 2020-08-14 Abdeslam Touri , Samir Kabbaj

In this paper we prove a version of Gruss integral inequality for mappings with values in Hilbert C*-modules. Some applications for such functions are also given.

Operator Algebras · Mathematics 2014-07-10 Amir Ghasem Ghazanfari

We study the theory of a Hilbert space H as a module for a unital C*-algebra A from the point of view of continuous logic. We give an explicit axiomatization for this theory and describe the structure of all the representations which are…

Logic · Mathematics 2012-12-03 Camilo Argoty

Let $\mathcal{H}$ be a (separable) Hilbert space and $\{e_k\}_{k\geq 1}$ a fixed orthonormal basis of $\mathcal{H}$. Motivated by many papers on scaled projections, angles of subspaces and oblique projections, we define and study the notion…

Functional Analysis · Mathematics 2007-05-23 Jorge Antezana , Gustavo Corach , Mariano Ruiz , Demetrio Stojanoff

We investigate the notion of conditionally positive definite in the context of Hilbert $C^*$-modules and present a characterization of the conditionally positive definiteness in terms of the usual positive definiteness. We give a Kolmogorov…

Operator Algebras · Mathematics 2017-09-26 Mohammad Sal Moslehian

We investigate the structured frames for Hilbert $C^{*}$-modules. In the case that the underlying $C^{*}$-algebra is a commutative $W^*$-algebra, we prove that the set of the Parseval frame generators for a unitary operator group can be…

Functional Analysis · Mathematics 2007-05-23 Wu Jing , Deguang Han , Ram Mohapatra

Certain results about frames are extended for the new frames in Hilbert C*-modules. In this paper, we introduce the notion of A-2-frames in A-2-inner product spaces and give some characterizations for these frames. Then we define the tensor…

Functional Analysis · Mathematics 2022-08-16 B. Mohebbi Najmabadi , T. L. Shateri

This note concerns a further study about Riesz-Fischer maps, already introduced by the author in a recent work, that is a notion that extends to the spaces of distributions the sequences that are known as Riesz-Fischer sequences. In…

Functional Analysis · Mathematics 2022-12-23 Francesco Tschinke

We show that every frame for a Hilbert space H can be written as a (multiple of a) sum of three orthonormal bases for H. A result of N.J. Kalton is included which shows that this is best possible in that: A frame can be represented as a…

Functional Analysis · Mathematics 2007-05-23 Peter G. Casazza

We study completely positive module maps on $C^{*}$-algebras which are $C^*$-module over another $C^*$-algebra with compatible actions. We extend several well known dilation and extension results to this setup, including the Stinespring…

Operator Algebras · Mathematics 2016-10-04 Massoud Amini

A regular operator T on a Hilbert C^*-module is defined just like a closed operator on a Hilbert space, with the extra condition that the range of (I+T^*T) is dense. Semiregular operators are a slightly larger class of operators that may…

Operator Algebras · Mathematics 2007-05-23 Arupkumar Pal

We describe algorithms for computing geometric invariants for Hilbert modular surfaces, and we report on their implementation.

Recently proved weighted Cauchy Scwarz inequality for Hilbert $C^*$-modules leads to many H\"older type inequalities for unitarily invariant norms on Hilbert space operators.

Functional Analysis · Mathematics 2019-07-02 Dragoljub J. Kečkić

We single out the concept of concrete Hilbert module over a locally $C^*$-algebra by means of locally bounded operators on certain strictly inductive limits of Hilbert spaces. Using this concept, we construct an operator model for all…

Operator Algebras · Mathematics 2025-11-04 Aurelian Gheondea