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In [11] the authors investigated a family of quotient Hilbert modules in the Cowen-Douglas class over the unit disk constructed from classical Hilbert modules such as the Hardy and Bergman modules. In this paper we extend the results to the…

Functional Analysis · Mathematics 2013-07-05 Ronald G. Douglas , Yun-Su Kim , Hyun-Kyoung Kwon , Jaydeb Sarkar

We construct a large family of positive-definite kernels $K: \mathbb{D}^n\times \mathbb{D}^n \to \mbox{M} (r, \mathbb C)$, holomorphic in the first variable and anti-holomorphic in the second, that are quasi-invariant with respect to the…

Functional Analysis · Mathematics 2023-01-10 Prahllad Deb , Somnath Hazra

It is known that all the vector bundles of the title can be obtained by holomorphic induction from representations of a certain parabolic group on finite dimensional inner product spaces. The representations, and the induced bundles, have…

Functional Analysis · Mathematics 2015-08-03 Adam Koranyi , Gadadhar Misra

We establish a connection between the de Branges-Rovnyak spaces and the Cowen-Douglas class of operators which is associated with complex geometric structures. We prove that the backward shift operator on a de Branges-Rovnyak space never…

Functional Analysis · Mathematics 2025-04-08 Emmanuel Fricain , Jaydeb Sarkar

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

The classical Cowen-Douglas class of (commuting tuples of) operators possessing an open set of (joint) eigenvalues of finite constant multiplicity was introduced by Cowen and Douglas, generalizing the backward shifts. Their unitary…

Operator Algebras · Mathematics 2025-03-12 Prahllad Deb , Victor Vinnikov

We introduce and study some new uniform structures for Hilbert $C^*$-modules over an algebra $A$. In particular, we prove that in some cases they have the same totally bounded sets. To define one of them, we introduce a new class of…

Operator Algebras · Mathematics 2024-02-29 Denis Fufaev , Evgenij Troitsky

In this paper we construct a class of homogeneous Hilbert modules over the disc algebra $\mathcal{A}(\mathbb D)$ as quotients of certain natural modules over the function algebra $\mathcal{A}(\mathbb D^2)$. These quotient modules are…

Functional Analysis · Mathematics 2007-05-23 Gadadhar Misra , Subrata Shyam Roy

Linear spaces with an Euclidean metric are ubiquitous in mathematics, arising both from quadratic forms and inner products. Operators on such spaces also occur naturally. In recent years, the study of multivariate operator theory has made…

Functional Analysis · Mathematics 2019-01-15 Gadadhar Misra

The study of Cowen-Douglas operators involves not only operator-theoretic tools but also complex geometry on holomorphic vector bundles. By leveraging the properties of holomorphic vector bundles, this paper investigates the cyclicity of…

Functional Analysis · Mathematics 2025-01-22 Jing Xu , Shanshan Ji , Yufang Xie , Kui Ji

Noncommutative K\"ahler structures were recently introduced as an algebraic framework for studying noncommutative complex geometry on quantum homogeneous spaces. In this paper, we introduce the notion of a \emph{compact quantum homogeneous…

Quantum Algebra · Mathematics 2026-03-17 Biswarup Das , Réamonn Ó Buachalla , Petr Somberg

The direct sum of irreducible level one integrable representations of affine Kac-Moody Lie algebra of (affine) type $ADE$ carries a structure of $P/Q$-graded vertex operator algebra. There exists a filtration on this direct sum studied by…

Representation Theory · Mathematics 2019-02-20 Evgeny Feigin , Ievgen Makedonskyi

We are concerned with the similarity problem for Cowen-Douglas operator tuples. The unitary equivalence counterpart was already investigated in the 1970's and geometric concepts including vector bundles and curvature appeared in the…

Functional Analysis · Mathematics 2022-12-09 Kui Ji , Shanshan Ji , Hyun-Kyoung Kwon , Jing Xu

The study of Cowen-Douglas operators not only involves traditional operator-theoretic tools but also concepts and results from complex geometry on holomorphic vector bundles. We make use of the ratio of the metric matrices first considered…

Functional Analysis · Mathematics 2025-06-24 Kui Ji , Shanshan Ji , Hyun-Kyoung Kwon , Jing Xu

In this paper we define difference operators and homogeneous Sobolev-type spaces on the dual of a compact Lie group. As an application and to show that this defines a relevant differential structure, we state and prove multiplier theorems…

Functional Analysis · Mathematics 2018-06-12 Veronique Fischer

This text can be considered as a non-technical and arithmetically motivated introduction to the definition of the limiting mixed Hodge structure. We state several assertions in terms natural to the classical theory of ordinary differential…

Number Theory · Mathematics 2023-10-05 Masha Vlasenko

We give a generalization of the Hodge operator to spaces $(V,h)$ endowed with a hermitian or symmetric bilinear form $h$ over arbitrary fields, including the characteristic two case. Suitable exterior powers of $V$ become free modules over…

Group Theory · Mathematics 2024-10-15 Linus Kramer , Markus J. Stroppel

Let H be an infinite-dimensional (real or complex) Hilbert space, viewed as a metric structure in its natural signature. We characterize the definable linear operators on H as exactly the "scalar plus compact" operators.

Logic · Mathematics 2010-10-13 Isaac Goldbring

The defining conditions for the irreducible tensor operators associated with the unitary irreducible corepresentions of compact quantum group algebras are deduced first in both the right and left regular coaction formalisms. In each case it…

q-alg · Mathematics 2016-09-08 J. F. Cornwell

Let $\mathcal{A}$ denote the operator class in which every nonzero intertwiner between two operators in $\mathcal{A}$ has dense range. Utilizing the operators in $\mathcal{A}$ as atoms and the flag structure as connection, we introduce an…

Functional Analysis · Mathematics 2025-08-26 Xie yufang , Ji shanshan , Xu jing , Ji Kui