On the two-dimensional moment problem.
-adic analytic interpolation
Pick-Nevanlinna interpolation on finitely-connected domains
Let Ω be a domain in the complex plane bounded by m+1 disjoint, analytic simple closed curves and let be n+1 distinct points in Ω. We show that for each (n+1)-tuple of complex numbers, there is a unique analytic function B such that: (a) B is continuous on the closure of Ω and has constant modulus on each component of the boundary of Ω; (b) B has n or fewer zeros in Ω; and (c) , 0 ≤ j ≤ n.
Problème des moments matriciels sur la droite : construction d'une famille de solutions et questions d'unicité
Regularization of a discrete backward problem using coefficients of truncated Lagrange polynomials.
Restricted interpolation by meromorphic inner functions
Meromorphic Inner Functions (MIFs) on the upper half plane play an important role in applications to spectral problems for differential operators. In this paper, we survey some recent results concerning function theoretic properties of MIFs and show their connections with spectral problems for the Schrödinger operator.
Sampling Sets for the Nevanlinna class.
Sets of interpolation and sampling for weighted Banach spaces of holomorphic functions
We give an elementary approach which allows us to evaluate Seip's conditions characterizing interpolating and sampling sequences in weighted Bergman spaces of infinite order for a wide class of weights depending on the distance to the boundary of the domain. Our results also give some information on cases not covered by Seip's theory. Moreover, we obtain new criteria for weights to be essential.
Spectral versus classical Nevanlinna-Pick interpolation in dimension two.
Stieltjes moment problem in general Gelfand-Shilov spaces
The Stieltjes moment problem is studied in the framework of general Gelfand-Shilov spaces, subspaces of the space of rapidly decreasing smooth complex functions, which are defined by imposing suitable bounds on their elements in terms of a given sequence M. Necessary and sufficient conditions on M are stated for the problem to have a solution, sometimes coming with linear continuous right inverses of the moment map, sending a function to the sequence of its moments. On the way, some results on the...
The construction of a function given by moments. (La construction de quelque fonction par des moments donnés.)
The Dirichlet space: a survey.
The Nevanlinna Matrix of Entire Functions Associated with a Shifted Indeterminate Hamburger Moment Problem.
Über die Verteilung der Curtiss-Maximalpunkte bei analytischen Jordankurven.
Über orthonormale Polynome und ein assoziiertes Momentenproblem.
Ultraconvergence et singularités pour une classe de séries d'exponentielles
Localisation des singularités des fonctions analytiques définies par des séries du type exp, où les sont complexes et où les sont des polynômes tayloriens, en utilisant des propriétés obtenues selon deux méthodes originellement dues l’une à B. Lepson pour les séries d’exponentielles à coefficients polynomiaux et dont la suite des exposants est une -suite et l’autre à G. L. Luntz pour les séries de Taylor-Dirichlet. Le résultat fondamental utilise un théorème de A. F. Leont’ev-G. P. Lapin...
Uniform controllability for the beam equation with vanishing structural damping
This paper is devoted to studying the effects of a vanishing structural damping on the controllability properties of the one dimensional linear beam equation. The vanishing term depends on a small parameter . We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls as goes to zero. It is shown that for any time sufficiently large but independent of and for each initial data in a suitable space there exists a uniformly bounded...
Uniform controllability of the linear one dimensional Schrödinger equation with vanishing viscosity
This article considers the linear 1-d Schrödinger equation in (0,π) perturbed by a vanishing viscosity term depending on a small parameter ε > 0. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls vε as ε goes to zero. It is shown that, for any time T sufficiently large but independent of ε and for each initial datum in H−1(0,π), there exists a uniformly...
Uniform controllability of the linear one dimensional Schrödinger equation with vanishing viscosity
This article considers the linear 1-d Schrödinger equation in (0,π) perturbed by a vanishing viscosity term depending on a small parameter ε > 0. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls vε as ε goes to zero. It is shown that, for any time T sufficiently large but independent of ε and for each initial datum in H−1(0,π), there exists a uniformly...
Uniform minimality, unconditionality and interpolation in backward shift invariant subspaces
We discuss relations between uniform minimality, unconditionality and interpolation for families of reproducing kernels in backward shift invariant subspaces. This class of spaces contains as prominent examples the Paley-Wiener spaces for which it is known that uniform minimality does in general neither imply interpolation nor unconditionality. Hence, contrarily to the situation of standard Hardy spaces (and of other scales of spaces), changing the size of the space seems necessary to deduce unconditionality...