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Related papers: Commutator lifting inequalities and interpolation

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The fundamental theorem on commutant lifting due to Sarason does not carry over to the setting of the polydisc. This paper presents two classifications of commutant lifting in several variables. The first classification links the lifting…

Functional Analysis · Mathematics 2025-09-09 Deepak K. D. , Jaydeb Sarkar

This paper concerns a commutant lifting theorem and a Nevanlinna-Pick type interpolation result in the setting of multipliers from vector-valued Drury-Arveson space to a large class of vector-valued reproducing kernel Hilbert spaces over…

Functional Analysis · Mathematics 2019-12-04 Deepak K. D. , Deepak Pradhan , Jaydeb Sarkar , Dan Timotin

We solve the commutant lifting and interpolation problems in the setting of the Hardy space and Schur functions on the open unit ball of $\mathbb{C}^n$. Our solutions also signify the role of inner functions on the unit ball, objects whose…

Complex Variables · Mathematics 2025-12-15 Jaydeep Bhattacharjee , Deepak K. D. , Jaydeb Sarkar

In this paper, through the introduction of partial multiple weights, we firstly study the related Rubio de Francia extrapolation theorem within the framework of partial Muckenhoupt classes and further obtain the corresponding extrapolation…

Classical Analysis and ODEs · Mathematics 2025-05-28 Wang Dinghuai , Yin Huicheng

This paper presents a few additions to commutant lifting theory. An operator interpolation problem is introduced and shown to be equivalent to the relaxed commutant lifting problem. Using this connection a description of all solutions of…

Functional Analysis · Mathematics 2007-05-23 A. E. Frazho , S. ter Horst , M. A. Kaashoek

An indefinite generalization of Nudel'man's problem is used in a systematic approach to interpolation theorems for generalized Schur and Nevanlinna functions with interior and boundary data. Besides results on existence criteria for…

Functional Analysis · Mathematics 2007-05-23 D. Alpay , T. Constantinescu , A. Dijksma , J. Rovnyak

In this paper we obtain a noncommutative multivariable analogue of the classical Nevanlinna-Pick interpolation problem for analytic functions with positive real parts on the open unit disc. As consequences, we deduce some results concerning…

Functional Analysis · Mathematics 2009-02-04 Gelu Popescu

General results of interpolation (eg. Nevanlinna-Pick) by elements in the noncommutative analytic Toeplitz algebra $F^\infty$ (resp. noncommutative disc algebra $A_n$) with consequences to the interpolation by bounded operator-valued…

Functional Analysis · Mathematics 2016-09-07 Alvaro Arias , Gelu Popescu

Our two principle goals are generalizations of the commutant lifting theorem and the Nevanlinna-Pick interpolation theorem to the context of Hardy algebras built from $W^*$-correspondences endowed with a sequence of weights. These theorems…

Operator Algebras · Mathematics 2016-08-18 Jennifer R Good

The article deals with isometric dilation and commutant lifting for a class of $n$-tuples $(n \geq 3)$ of commuting contractions. We show that operator tuples in the class dilate to tuples of commuting isometries of BCL type. As a…

Functional Analysis · Mathematics 2025-08-08 B. Krishna Das , Samir Panja

In this article we study commutant lifting, more generally intertwining lifting, for different reproducing kernel Hilbert spaces over two domains in $\mathbb{C}^n$, namely the unit ball and the unit polydisc. The reproducing kernel Hilbert…

Functional Analysis · Mathematics 2020-04-07 Sibaprasad Barik , Monojit Bhattacharjee , B. Krishna Das

We obtain dilation results which simultaneously generalize Sz.-Nagy dilation theorem for contractions, Ando's dilation theorem for commuting contractions, Sz.-Nagy--Foias commutant lifting theorem, and Schur's representation for the unit…

Functional Analysis · Mathematics 2017-01-12 Gelu Popescu

This paper is devoted to studying the Rubio de Francia extrapolation for multilinear compact operators. It allows one to extrapolate the compactness of $T$ from just one space to the full range of weighted spaces, whenever an $m$-linear…

Classical Analysis and ODEs · Mathematics 2023-04-06 Mingming Cao , Andrea Olivo , Kôzô Yabuta

A new functional model for pairs of commuting isometries is described. Intertwining operators between such models are then studied in order to approach the classification of invariant subspaces of such pairs.

Spectral Theory · Mathematics 2008-05-27 H. Bercovici , R. G. Douglas , C. Foias

We show that every multivariable contractive weighted shift dilates to a tuple of commuting unitaries, and hence satisfies von Neumann's inequality. This answers a question of Lubin and Shields. We also exhibit a closely related $3$-tuple…

Functional Analysis · Mathematics 2020-09-21 Michael Hartz

We obtain intertwining dilation theorems for noncommutative regular domains D_f and noncommutative varieties V_J of n-tuples of operators, which generalize Sarason and Sz.-Nagy--Foias commutant lifting theorem for commuting contractions. We…

Functional Analysis · Mathematics 2017-01-04 Gelu Popescu

We present a new, elementary proof of Boyd's interpolation theorem. Our approach naturally yields a noncommutative version of this result and even allows for the interpolation of certain operators on l^1-valued noncommutative symmetric…

Functional Analysis · Mathematics 2013-06-11 Sjoerd Dirksen

In a previous paper, we obtained several "compact versions" of Rubio de Francia's weighted extrapolation theorem, which allowed us to extrapolate the compactness of linear operators from just one space to the full range of weighted Lebesgue…

Functional Analysis · Mathematics 2022-02-23 Tuomas Hytönen , Stefanos Lappas

The theory of Nevanlinna-Pick and Carath\'eodory-Fej\'er interpolation for matrix- and operator-valued Schur class functions on the unit disk is now well established. Recent work has produced extensions of the theory to a variety of…

Functional Analysis · Mathematics 2008-08-19 J. A. Ball , S. ter Horst

We prove several noncommutative maximal inequalities associated with convex functions, including a Doob type inequality for a convex function of maximal operators on noncommutative martingales, noncommutative Dunford-Schwartz and Stein…

Operator Algebras · Mathematics 2014-12-31 Turdebek N. Bekjan , Zeqian Chen , Adam Osȩkowski
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