English

The Borel map in the mixed Beurling setting

Functional Analysis 2022-12-29 v2 Classical Analysis and ODEs Complex Variables

Abstract

The Borel map takes a smooth function to its infinite jet of derivatives (at zero). We study the restriction of this map to ultradifferentiable classes of Beurling type in a very general setting which encompasses the classical Denjoy-Carleman and Braun-Meise-Taylor classes. More precisely, we characterize when the Borel image of one class covers the sequence space of another class in terms of the two weights that define the classes. We present two independent solutions to this problem, one by reduction to the Roumieu case and the other by dualization of the involved Fr\'echet spaces, a Phragm\'en-Lindel\"of theorem, and H\"ormander's solution of the ˉ\bar{\partial}-problem.

Keywords

Cite

@article{arxiv.2205.08195,
  title  = {The Borel map in the mixed Beurling setting},
  author = {David Nicolas Nenning and Armin Rainer and Gerhard Schindl},
  journal= {arXiv preprint arXiv:2205.08195},
  year   = {2022}
}

Comments

33 pages; some typos corrected

R2 v1 2026-06-24T11:19:36.131Z