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20072025
most citedExtremal holomorphic maps and the symmetrised bidisc

40 citations · 97 across the 15 of their papers we have counts for

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16 papers · 1 filter

math.CV2025

Models of holomorphic functions on the symmetrized skew bidisc

Connor Evans, Zinaida A. Lykova, N. J. Young

The purpose of this paper is to develop the theory of holomorphic functions with modulus bounded by on the symmetrized skew bidisc \[ \mathbb{G}_{r} \stackrel{\rm def}{=} \Big\…

math.CV2025

Boundary behavior of functions in the Schur-Agler class of the polydisc

Jim Agler, Connor Evans, Zinaida Lykova +1

We describe a generalization of the notion of a Hilbert space model of a function in the Schur-Agler class of the polydisc. This generalization is well adapted to the investiga…

math.CV2025

Function theory on the annulus in the dp-norm

Jim Agler, Zinaida Lykova, N. J. Young

In this paper we shall use realization theory to prove new results about a class of holomorphic functions on an annulus \[R_δ\stackrel{\rm def}{=} \{z \in \mathbb{C}: δ<|z|<1\},\]…

math.CV2024

Function theory in the bfd-norm on an elliptical region

Jim Agler, Zinaida Lykova, Nicholas Young

Let be the open region in the complex plane bounded by an ellipse. The B. and F. Delyon norm on the space of holomorphic functions…

math.CV2022

Nonuniqueness of Carathéodory extremal functions on the symmetrized bidisc

Jim Agler, Zinaida Lykova, N. J. Young

We survey the Carathéodory extremal problem on the symmetrized bidisc W…

math.CV2018★ 10 cited

Non-commutative manifolds, the free square root and symmetric functions in two non-commuting variables

Jim Agler, John E. McCarthy, N. J. Young

The richly developed theory of complex manifolds plays important roles in our understanding of holomorphic functions in several complex variables. It is natural to consider manifol…

math.CV2017

Carathéodory extremal functions on the symmetrized bidisc

Jim Agler, Zinaida Lykova, N. J. Young

We show how realization theory can be used to find the solutions of the Carathéodory extremal problem on the symmetrized bidisc \[ G \stackrel{\rm{def}}{=} \{(z+w,zw):|z|<1, \, |w|…

math.CV2017

Realization of functions on the symmetrized bidisc

Jim Agler, N. J. Young

We prove a realization formula and a model formula for analytic functions with modulus bounded by on the symmetrized bidisc \[ G\stackrel{\rm def}{=} \{(z+w,zw): |z|<1, \, |w|…

math.CV2013★ 1 cited

3-extremal holomorphic maps and the symmetrised bidisc

Jim Agler, Zinaida A. Lykova, N. J. Young

We analyse the 3-extremal holomorphic maps from the unit disc to the symmetrised bidisc , defined to be the set , with a…

math.CV2013★ 1 cited

Symmetric functions of two noncommuting variables

Jim Agler, N. J. Young

We prove a noncommutative analogue of the fact that every symmetric analytic function of in the bidisc $\D^2$ can be expressed as an analytic function of the variables $z+w…

math.CV2012★ 40 cited

Extremal holomorphic maps and the symmetrised bidisc

Jim Agler, Zinaida A. Lykova, N. J. Young

We introduce the class of -extremal holomorphic maps, a class that generalises both finite Blaschke products and complex geodesics, and apply the notion to the finite interpolat…

math.CV2012★ 2 cited

Boundary behavior of analytic functions of two variables via generalized models

J. Agler, R. Tully-Doyle, N. J. Young

We describe a generalization of the notion of a Hilbert space model of a function in the Schur class of the bidisc. This generalization is well adapted to the investigation of boun…

math.CV2010★ 1 cited

A Caratheodory theorem for the bidisk via Hilbert space methods

Jim Agler, John E. McCarthy, Nicholas J. Young

If $\ph$ is an analytic function bounded by 1 on the bidisk $\D^2$ and $τ\in\tb$ is a point at which $\ph$ has an angular gradient $\nabla\ph(τ)$ then $\nabla\ph(\la) \to \nabla\ph…

math.CV2009

Boundary Nevanlinna-Pick interpolation via reduction and augmentation

Jim Agler, N. J. Young

We give an elementary proof of Sarason's solvability criterion for the Nevanlinna-Pick problem with boundary interpolation nodes and boundary target values. We also give a concrete…

math.CV2007★ 37 cited

The automorphism group of the tetrablock

N. J. Young

The tetrablock is a domain in 3-dimensional complex space that meets 3-dimensional Euclidean space in a regular tetrahedron. It is shown to be inhomogeneous and its automorphism gr…

math.CV2007★ 5 cited

A Schwarz lemma for a domain related to mu-synthesis

A. A. Abouhajar, M. C. White, N. J. Young

We prove a Schwarz lemma for a domain E in 3-dimensional complex space that arises in connection with a problem in H infinity control theory. We describe a class of automorphisms o…