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Related papers: Orthogonally Additive Mappings on Hilbert Modules

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We study orthogonally additive operators between Riesz spaces without the Dedekind completeness assumption on the range space. Our first result gives necessary and sufficient conditions on a pair of Riesz spaces $(E,F)$ for which every…

Functional Analysis · Mathematics 2022-10-19 Olena Fotiy , Vladimir Kadets , Mikhail Popov

In this paper first we give a partial answer to a question of L. Moln\'ar and W. Timmermann. Namely, we will describe those linear (not necessarily bijective) transformations on the set of self-adjoint matrices which preserve a unitarily…

Functional Analysis · Mathematics 2015-07-13 György Pál Gehér , Gergő Nagy

In this paper, we consider natural Hilbert-space representations $\left\{ \left(\mathbb{C}^{2},\pi_{t}\right)\right\} _{t\in\mathbb{R}}$ of the hypercomplex system $\left\{ \mathbb{H}_{t}\right\} _{t\in\mathbb{R}}$, and study the…

Representation Theory · Mathematics 2023-01-23 Daniel Alpay , Ilwoo Cho

A densely-defined symmetric linear map from/to a real Hilbert space extends to a self-adjoint map. Extension is expressed via Riesz representation. For a case including Friedrichs extension of a strongly monotone map, self-adjoint extension…

Functional Analysis · Mathematics 2011-02-10 H. N. Friedel

Motivated by questions raised in the preprint [AL20] by Accardi and Lu (private communication), we examine criteria for when the product of two partial isometries between Hilbert spaces is again a partial isometry and we use this to define…

Operator Algebras · Mathematics 2025-09-05 Michael Skeide

A geometric extension algebra is an extension algebra of a semi-simple perverse sheaf (allowing shifts), e.g. a push-forward of the constant sheaf under a projective map. Particular nice situations arise for collapsings of homogeneous…

Representation Theory · Mathematics 2015-10-06 Julia Sauter

We determine the injective envelope and local multiplier algebra of a continuous trace C*-algebra that arises from a continuous Hilbert bundle over an arbitrary locally compact Hausdorff space. In addition, we show that the second-order…

Operator Algebras · Mathematics 2011-02-25 Martin Argerami , Douglas Farenick , Pedro Massey

Let $\mathcal{H}$ be a Hilbert space, and let $K(\mathcal{H})$ be the $C^*$-algebra of compact operators on $\mathcal{H}$. In this paper, we present some characterizations of the norm-parallelism for elements of a Hilbert…

Functional Analysis · Mathematics 2018-12-04 M. Mohammadi Gohari , M. Amyari

We find certain relations between flag Hilbert schemes of points on plane curves and moduli spaces of one-dimensional plane sheaves. We show that some of these moduli spaces are unirational.

Algebraic Geometry · Mathematics 2017-01-31 Mario Maican

Given a fixed binary form $f(u,v)$ of degree $d$ over a field $k$, the associated \emph{Clifford algebra} is the $k$-algebra $C_f=k\{u,v\}/I$, where $I$ is the two-sided ideal generated by elements of the form $(\alpha u+\beta…

Rings and Algebras · Mathematics 2010-09-13 Emre Coskun

The spectral factorization mapping $F\to F^+$ puts a positive definite integrable matrix function $F$ having an integrable logarithm of the determinant in correspondence with an outer analytic matrix function $F^+$ such that $F =…

Complex Variables · Mathematics 2019-07-31 Lasha Ephremidze , Eugene Shargorodsky , Ilya Spitkovsky

In general, it is a non trivial task to determine the adjoint $S^*$ of an unbounded operator $S$ acting between two Hilbert spaces. We provide necessary and sufficient conditions for a given operator $T$ to be identical with $S^*$. In our…

Functional Analysis · Mathematics 2017-11-23 Zoltán Sebestyén , Zsigmond Tarcsay

We introduce the concept of frame of multipliers in Hilbert modules over pro-C*-algebras and show that many properties of frames in Hilbert C*-modules are valid for frames of multipliers in Hilbert modules over pro-C*-algebras.

Operator Algebras · Mathematics 2007-09-07 Maria Joita

In this note we prove that elementary maps on triangular algebras are automically additive.

Rings and Algebras · Mathematics 2007-06-13 Xuehan Cheng , Wu Jing

A precise description of the injective envelope of a spatial continuous trace C*-algebra A over a Stonean space Delta is given. The description is based on the notion of a weakly continuous Hilbert bundle, which we show to be a…

Operator Algebras · Mathematics 2012-07-09 Martin Argerami , Douglas Farenick , Pedro Massey

In a recent paper of the first author and Kashyap, a new class of modules over dual operator algebras is introduced. These generalize the W*-modules (that is, Hilbert C*-modules over a von Neumann algebra which satisfy an analogue of the…

Operator Algebras · Mathematics 2009-10-29 David P Blecher , Jon E Kraus

Let F be a right Hilbert C*-module over a C*-algebra B, and suppose that F is equipped with a left action, by compact operators, of a second C*-algebra A. Tensor product with F gives a functor from Hilbert C*-modules over A to Hilbert…

Operator Algebras · Mathematics 2020-06-19 Tyrone Crisp

In the present paper we develop both ideas of D. Baki\'c and B. Gulja{\v{s}} and the categorical approach to multipliers from E.C. Lance's book and publications of the second author, for the introduction and study of left multipliers of…

Operator Algebras · Mathematics 2025-04-29 Michael Frank , Alexander A. Pavlov

The paper is devoted to continuous frames and Riesz bases in Hilbert C*-modules. we define a continuous Riesz basis for Hilbert C*-modules and give some results about them.

Functional Analysis · Mathematics 2022-09-20 Hadi Ghasemi , Tayebe Lal Shateri

We consider a class of C*-algebras associated to one parameter continuous tensor product systems of Hilbert modules, which can be viewed as continuous counterparts of Pimsner's Toeplitz algebras. By exhibiting a homotopy of…

Operator Algebras · Mathematics 2007-05-23 Ilan Hirshberg