English
Related papers

Related papers: B-Valued Free Convolution for Unbounded Operators

200 papers

For a closed densely defined operator $T$ from a Hilbert space $\mathfrak{H}$ to a Hilbert space $\mathfrak{K}$, necessary and sufficient conditions are established for the factorization of $T$ with a bounded nonnegative operator $X$ on…

Functional Analysis · Mathematics 2025-07-21 Yosra Barkaoui , Seppo Hassi

Let $X$ be a finite connected graph, each of whose vertices has degree at least three. The fundamental group $\Gamma$ of $X$ is a free group and acts on the universal covering tree $\Delta$ and on its boundary $\partial \Delta$, endowed…

Operator Algebras · Mathematics 2013-02-25 Guyan Robertson

We provide bounds of Berry-Esseen type for fundamental limit theorems in operator-valued free probability theory such as the operator-valued free Central Limit Theorem and the asymptotic behaviour of distributions of operator-valued…

Probability · Mathematics 2022-03-01 Marwa Banna , Tobias Mai

We provide the necessary and sufficient conditions for a generalized Nevanlinna function $Q$ ($Q\in N_{\kappa }\left( \mathcal{H} \right)$) to be a Weyl function (also known as a Weyl-Titchmarch function). We also investigate an important…

Functional Analysis · Mathematics 2025-03-25 Muhamed Borogovac

There are presented certain results on extending continuous linear operators defined on spaces of E-valued continuous functions (defined on a compact Hausdorff space X) to linear operators defined on spaces of E-valued measurable functions…

Functional Analysis · Mathematics 2017-05-26 Piotr Niemiec

In this note we quantize the free $ * $-algebra generated by finitely many variables, which is a new example of the theory of Toeplitz quantization of $ * $-algebras as developed previously by the author. This is achieved by defining…

Mathematical Physics · Physics 2019-05-06 Stephen Bruce Sontz

Let $X$ be a Banach space and $\mathcal A$ be the Banach algebra $B(X)$ of bounded (i.e. continuous) linear transformations (to be called operators) on $X$ to itself. Let $\mathcal E$ be the set of idempotents in $\mathcal A$ and $\mathcal…

Functional Analysis · Mathematics 2024-11-18 Surender K. Jain , André Leroy , Ajit Iqbal Singh

We consider a version of a famous open problem formulated by Kadison, asking whether bounded representations of operator algebras are automatically completely bounded. We investigate this question in the context of amenable operator…

Operator Algebras · Mathematics 2017-08-02 Raphaël Clouâtre , Laurent W. Marcoux

The Heisenberg Oscillator Algebra admits irreducible representations both on the ring $B$ of polynomials in infinitely many indeterminates (the {\em bosonic representation}) and on a graded-by-{\em charge} vector space, the {\em…

Algebraic Geometry · Mathematics 2013-10-21 Letterio Gatto , Parham Salehyan

Let T and C be two Hilbert space operators. We prove that if T is near, in a certain sense, to an operator completely polynomially dominated with a finite bound by C, then T is similar to an operator which is completely polynomially…

Functional Analysis · Mathematics 2007-05-23 C. Badea

The well known Douglas Lemma says that for operators $A,B$ on Hilbert space that $AA^*-BB^*\succeq 0$ implies $B=AC$ for some contraction operator $C$. The result carries over directly to classical operator-valued Toeplitz operators by…

Functional Analysis · Mathematics 2014-11-10 Sriram Balasubramanian

The purpose of the paper is to study the operators on the weighted Bergman spaces on the unit disk ${\mathbb{D}}$, denoted by $A^{p}_{\lambda,w}({\mathbb{D}})$, that are associated with a class of generalized analytic functions, named the…

Complex Variables · Mathematics 2022-09-20 Zhongkai Li , Haihua Wei

We consider the action of finitely truncated singular integral operators on functions taking values in a Banach space. Such operators are bounded for any Banach space, but we show a quantitative improvement over the trivial bound in any…

Functional Analysis · Mathematics 2023-10-16 Tuomas Hytönen

We explore commutativity up to a factor, $AB=\lambda BA$, for bounded operators in a complex Hilbert space. Conditions on the possible values of the factor $\lambda$ are formulated and shown to depend on spectral properties of the operators…

Functional Analysis · Mathematics 2009-10-31 J. A. Brooke , P. Busch , D. B. Pearson

We discuss the reflexivity of hyperexpansions and their Cauchy dual operators. In particular, we show that any cyclic completely hyperexpansive operator is reflexive. We also establish the reflexivity of the Cauchy dual of an arbitrary…

Functional Analysis · Mathematics 2019-12-17 Shubhankar Podder , Deepak Kumar Pradhan

We prove a Cauchy identity for free quasi-symmetric functions and apply it to the study of various bases. A free Weyl formula and a generalization of the splitting formula are also discussed.

Combinatorics · Mathematics 2013-02-12 Gerard H. E. Duchamp , Florent Hivert , Jean-Christophe Novelli , Jean-Yves Thibon

Let $G$ be a locally compact abelian group, let $\nu$ be a regular probability measure on $G$, let $X$ be a Banach space, let $\pi\colon G\to B(X)$ be a bounded strongly continuous representation. Consider the average (or subordinated)…

Functional Analysis · Mathematics 2017-07-17 Florence Lancien , Christian Le Merdy

In [9], we observed Amalgamated R-transform Theory. Different from the original definition of Voiculescu and Speicher, we define R-transforms of operator-valued random variable(s) by operator-valued formal series. By doing that we can…

Operator Algebras · Mathematics 2007-05-23 Ilwoo Cho

We continue our program of unifying general relativity and quantum mechanics in terms of a noncommutative algebra ${\cal A}$ on a transformation groupoid $\Gamma = E \times G$ where $E$ is the total space of a principal fibre bundle over…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Michael Heller , Leszek Pysiak , Wieslaw Sasin

We introduce a new class which generalizes the class of B-Weyl operators. We say that $T\in L(X)$ is pseudo B-Weyl if $T=T_1\oplus T_2$ where $T_1$ is a Weyl operator and $T_2$ is a quasi-nilpotent operator. We show that the corresponding…

Functional Analysis · Mathematics 2015-03-24 H. Zariouh , H. Zguitti