• Dirichlet Approximation and Universal Dirichlet 

      [OWP-2016-12] Aron, Richard M.; Bayart, Frédéric; Gauthier, Paul Montpetit; Maestre, Manuel; Nestoridis, Vassili (Mathematisches Forschungsinstitut Oberwolfach, 2016-08-16)
      We characterize the uniform limits of Dirichlet polynomials on a right half plane. We extend the approximation theorems of Runge, Mergelyan and Vitushkin to the Dirichlet setting with respect to the Euclidean distance and ...
    • A Function Algebra Providing New Mergelyan Type Theorems in Several Complex Variables 

      [OWP-2019-02] Falcó, Javier; Gauthier, Paul Montpetit; Manolaki, Myrto; Nestoridis, Vassili (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-11)
      For compact sets $K\subset \mathbb C^{d}$, we introduce a subalgebra $A_{D}(K)$ of $A(K)$, which allows us to obtain Mergelyan type theorems for products of planar compact sets as well as for graphs of functions.
    • Non-Extendability of Holomorphic Functions with Bounded or Continuously Extendable Derivatives 

      [OWP-2017-30] Moschonas, Dionysios; Nestoridis, Vassili (Mathematisches Forschungsinstitut Oberwolfach, 2017-10-21)
      We consider the spaces $H_{F}^{\infty}(\Omega)$ and $\mathcal{A}_{F}(\Omega)$ containing all holomorphic functions $f$ on an open set $\Omega \subseteq \mathbb{C}$, such that all derivatives $f^{(l)}$, $l\in F \subseteq ...
    • Rational Approximation on Products of Planar Domains 

      [OWP-2016-05] Aron, Richard M.; Gauthier, Paul Montpetit; Maestre, Manuel; Nestoridis, Vassili; Falcó, Javier (Mathematisches Forschungsinstitut Oberwolfach, 2016-06-17)
      We consider $A(\Omega)$, the Banach space of functions $f$ from $ \overline{\Omega}=\prod_{i \in I} \overline{U_i}$ to $\mathbb{C}$ that are continuous with respect to the product topology and separately holomorphic, where ...
    • Spherical Arc-Length as a Global Conformal Parameter for Analytic Curves in the Riemann Sphere 

      [OWP-2016-21] Gauthier, Paul Montpetit; Nestoridis, Vassili; Papadopoulos, Athanase (Mathematisches Forschungsinstitut Oberwolfach, 2016-11-11)
      We prove that for every analytic curve in the complex plane $\mathbb{C}$, Euclidean and spherical arc-lengths are global conformal parameters. We also prove that for any analytic curve in the hyperbolic plane, hyperbolic ...