English

Pathological phenomena in Denjoy-Carleman classes

Classical Analysis and ODEs 2016-02-11 v2 Complex Variables

Abstract

Let CM\mathcal C^M denote a Denjoy-Carleman class of C\mathcal C^\infty functions (for a given logarithmically-convex sequence M=(Mn)M = (M_n)). We construct: (1) a function in CM((1,1))\mathcal C^M((-1,1)) which is nowhere in any smaller class; (2) a function on R\mathbb R which is formally CM\mathcal C^M at every point, but not in CM(R)\mathcal C^M(\mathbb R); (3) (under the assumption of quasianalyticity) a smooth function on Rp\mathbb R^p (p2p \geq 2) which is CM\mathcal C^M on every CM\mathcal C^M curve, but not in CM(Rp)\mathcal C^M(\mathbb R^p).

Keywords

Cite

@article{arxiv.1408.4092,
  title  = {Pathological phenomena in Denjoy-Carleman classes},
  author = {Ethan Y. Jaffe},
  journal= {arXiv preprint arXiv:1408.4092},
  year   = {2016}
}

Comments

21 pages

R2 v1 2026-06-22T05:32:26.970Z