English

A Rudin-Carleson theorem with uniform approximation for manifold-valued maps

Complex Variables 2026-07-18 v1

Abstract

Given a closed set EDE \subset \partial {\mathbb D} of measure zero and a continuous function φ:EC\varphi : E \to {\mathbb C}, the classical Rudin-Carleson interpolation theorem states that there exists a continuous function F:DCF : \overline {\mathbb D} \to {\mathbb C} that is holomorphic on D{\mathbb D} and satisfies FE=φF\rvert_E = \varphi. In this paper we obtain a generalisation of the Rudin-Carleson theorem for maps φ:EX\varphi : E \to X into arbitrary connected complex manifolds XX that combines interpolation of φ\varphi on EE with uniform approximation on compact subsets of DE\overline {\mathbb D} \setminus E of another given continuous map f:DXf:\overline {\mathbb D} \to X that is holomorphic on D{\mathbb D}. Under the further assumption that XX is an Oka manifold we obtain a corollary that combines Rudin-Carleson interpolation of a continuous map φ:DX\varphi : \overline {\mathbb D} \to X on EE with Runge approximation of φ\varphi on a compact set KDK\subset {\mathbb D} without any holes on which φ\varphi is holomorphic.

Keywords

Cite

@article{arxiv.2607.16843,
  title  = {A Rudin-Carleson theorem with uniform approximation for manifold-valued maps},
  author = {Benedikt Steinar Magnússon and Tyson Ritter},
  journal= {arXiv preprint arXiv:2607.16843},
  year   = {2026}
}