English

On a problem by Hans Feichtinger

Classical Analysis and ODEs 2018-12-11 v3

Abstract

In this paper, we solve a spectral problem about positive semi-definite trace-class pseudodifferential operators on modulation spaces which was posed by H. Feichtinger. Later, C. Heil and D. Larson rephrased the problem in the broader setting of positive semi-definite trace-class operators on a separable Hilbert space. Our solution consists in constructing a counterexample that solves Hans Feichtinger's problem by first solving this second problem.

Keywords

Cite

@article{arxiv.1705.06392,
  title  = {On a problem by Hans Feichtinger},
  author = {Radu Balan and Kasso A. Okoudjou and Anirudha Poria},
  journal= {arXiv preprint arXiv:1705.06392},
  year   = {2018}
}
R2 v1 2026-06-22T19:50:36.527Z