English

Uncertainty Principle for distributions with Fourier transform in $L_{p,q}(\mathbb{R}^d)$

Classical Analysis and ODEs 2026-04-30 v1

Abstract

A version of the Uncertainty Principle says: There does not exist a non zero function in Lp(Rd)L_p(\mathbb{R}^d) if its Fourier transform is supported by a set of finite α\alpha-Hausdorff measure with α<2d/p\alpha<2d/p. This UP does not hold at the endpoint α=2d/p\alpha=2d/p. We find the sharp form of the UP in the limit case. We prove that there exists a non-zero function in the Lorentz space Lp,q(Rd)L_{p,q}(\mathbb{R}^d) such that its Fourier transform is supported by a set of zero (2dp,β)(\frac{2d}{p},\beta)-Netrusov--Hausdorff capacity if and only if β>q2(q1)\beta>\frac{q}{2(q-1)}.

Keywords

Cite

@article{arxiv.2604.26096,
  title  = {Uncertainty Principle for distributions with Fourier transform in $L_{p,q}(\mathbb{R}^d)$},
  author = {Nikita Dobronravov},
  journal= {arXiv preprint arXiv:2604.26096},
  year   = {2026}
}