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Related papers: Three-point Nevanlinna Pick problem in the polydis…

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Recent work of Kosi\'nski on the three point Pick interpolation problem on the polydisc proves the von Neumann inequality for 3x3 matrices. We give a detailed explanation of this using several standard reductions---credit for the main…

Complex Variables · Mathematics 2020-02-19 Greg Knese

We give a new proof on the disk that a Pick problem can be solved by a rational function that is unimodular on the unit circle and for which the number of poles inside the disk is no more than the number of non-positive eigenvalues of the…

Functional Analysis · Mathematics 2012-08-15 Jim Agler , Joseph A. Ball , John E. McCarthy

Recent results of Davidson-Paulsen-Raghupathi-Singh give necessary and sufficient conditions for the existence of a solution to the Nevanlinna-Pick interpolation problem on the unit disk with the additional restriction that the interpolant…

Functional Analysis · Mathematics 2020-03-02 J. A. Ball , V. Bolotnikov , S. ter Horst

Nevanlinna-Pick interpolation developed from a topic in classical complex analysis to a useful tool for solving various problems in control theory and electrical engineering. Over the years many extensions of the original problem were…

Functional Analysis · Mathematics 2022-05-30 Sanne ter Horst , Alma van der Merwe

Motivated by the recent progress of research on extending holomorphic functions defined on subvarieties of classical domains and its connections to the 3-point Pick interpolation, we study a special class of two-dimensional algebraic…

Complex Variables · Mathematics 2022-04-15 Krzysztof Maciaszek

We study several aspects concerning slice regular functions mapping the quaternionic open unit ball into itself. We characterize these functions in terms of their Taylor coefficients at the origin and identify them as contractive…

Complex Variables · Mathematics 2013-08-13 Daniel Alpay , Vladimir Bolotnikov , Fabrizio Colombo , Irene Sabadini

The main results presented in this paper provide a complete and explicit description of all solutions to the left tangential operator Nevanlinna- Pick interpolation problem assuming the associated Pick operator is strictly positive. The…

Functional Analysis · Mathematics 2018-04-24 A. E. Frazho , S. Ter Horst , M. A. Kaashoek

In the paper `Distinguished Varieties,' Agler and McCarthy used Hilbert function spaces to study the uniqueness properties of the Nevanlinna-Pick problem on the bidisc. In this work we give a geometric procedure for constructing a…

Functional Analysis · Mathematics 2011-05-04 David Scheinker

In the paper we discuss the problem of uniqueness of left inverses (solutions of two point Nevanlinna-Pick problem) in bounded convex domains, strongly linearly convex domains, the symmetrized bidisc and the tetrablock.

Complex Variables · Mathematics 2015-04-07 Ł. Kosiński , W. Zwonek

This article treats Nevanlinna-Pick interpolation in the setting of a special class of algebraic curves called distinguished varieties. An interpolation theorem, along with additional operator theoretic results, is given using a family of…

Functional Analysis · Mathematics 2013-02-06 Michael T. Jury , Greg Knese , Scott McCullough

Given a domain $\Omega$ in $\mathbb{C}^m$, and a finite set of points $z_1,\ldots, z_n\in \Omega$ and $w_1,\ldots, w_n\in \mathbb{D}$ (the open unit disc in the complex plane), the $Pick\, interpolation\, problem$ asks when there is a…

Functional Analysis · Mathematics 2021-04-13 Tirthankar Bhattacharyya , Anindya Biswas , Vikramjeet Singh Chandel

We describe the set of inner functions of finite order in a multi-connected domain, then we consider an optimization formulation of the Pick-Nevanlinna interpolation problem, and we generalize it to Hermite type interpolation.

Complex Variables · Mathematics 2025-11-20 Michel Crouzeix

We obtain necessary and sufficient conditions for Nevanlinna-Pick interpolation on the unit disk with the additional restriction that all analytic interpolating functions satisfy $f'(0)=0.$ Alternatively, these results can be interpreted as…

Operator Algebras · Mathematics 2007-11-14 Kenneth R. Davidson , Vern I. Paulsen , Mrinal Raghupathi , Dinesh Singh

We introduce the notion of a \lambda-nonisotropically balanced domain and show that the symmetrized polydisc in C^n, n \geq 2, is an example of such a domain. Given a \lambda-nonisotropically balanced domain \Omega, we derive effective…

Complex Variables · Mathematics 2007-05-23 Gautam Bharali

Three boundary Nevanlinna-Pick interpolation problems at finitely many points are formulated for generalized Schur functions. For each problem, the set of all solutions is parametrized in terms of a linear fractional transformation with a…

Complex Variables · Mathematics 2007-05-23 Vladimir Bolotnikov , Alexander Kheifets

We introduce the class of $n$-extremal holomorphic maps, a class that generalises both finite Blaschke products and complex geodesics, and apply the notion to the finite interpolation problem for analytic functions from the open unit disc…

Complex Variables · Mathematics 2020-04-28 Jim Agler , Zinaida A. Lykova , N. J. Young

There are three new things in this paper about the open symmetrized bidisk $\mathbb G = \{(z_1+z_2, z_1z_2) : |z_1|, |z_2| < 1\}$. They are motivated in the Introduction. In this Abstract, we mention them in the order in which they will be…

Functional Analysis · Mathematics 2017-12-05 Tirthankar Bhattacharyya , Haripada Sau

A seminal result of Agler characterizes the so-called Schur-Agler class of functions on the polydisk in terms of a unitary colligation transfer function representation. We generalize this to the unit ball of the algebra of multipliers for a…

Functional Analysis · Mathematics 2007-05-23 Michael A. Dritschel , Stefania Marcantognini , Scott McCullough

An approach to complex interpolation of compact subsets of $\Bbb C^n$, including Brunn-Minkowski type inequalities for the capacities of the interpolating sets, was developed recently by means of plurisubharmonic geodesics between relative…

Complex Variables · Mathematics 2021-02-18 Alexander Rashkovskii

Following ideas by Beardon, Minda and Baribeau, Rivard, Wegert in the context of the complex Schwarz-Pick Lemma, we use iterated hyperbolic difference quotients to prove a quaternionic multipoint Schwarz-Pick Lemma, in the context of the…

Complex Variables · Mathematics 2026-04-01 Cinzia Bisi , Davide Cordella