English

Global hypoellipticity for perturbations of complex vector fields on the torus

Analysis of PDEs 2026-02-25 v1

Abstract

We apply Kr\"{o}necker's approximation theorem to measure (in a topological sense) a set of constants which turn a vector field into a non-globally hypoelliptic operator. We present situations in which this set is a discrete enumerable (hence, meager) subset of the real line, and we also show that this set may be a dense Gδ\mathcal{G}_\delta subset of the complex numbers (hence, nonmeager), which produces a contrast to a known result stating that this set has null Lebesgue measure.

Keywords

Cite

@article{arxiv.2602.21159,
  title  = {Global hypoellipticity for perturbations of complex vector fields on the torus},
  author = {Maria V. Bartmeyer and Paulo L. Dattori da Silva and Rafael B. Gonzalez},
  journal= {arXiv preprint arXiv:2602.21159},
  year   = {2026}
}
R2 v1 2026-07-01T10:50:27.426Z