English

Wiener-Pitt sets for compact Abelian groups

Functional Analysis 2025-10-29 v1

Abstract

Suppose that GG is a compact Hausdorff Abelian group. We say μM(G)\mu \in M(G) is strongly continuous if μ(x+H)=0|\mu|(x+H)=0 for any xGx \in G and any HGH \leq G that is closed and of infinite index. We prove that for any sufficiently rapidly decreasing sequence (an)n=1c0(N)(a_{n})_{n=1}^{\infty}\in c_{0}(\mathbb{N}), for every strongly continuous μM(G)\mu\in M(G) with μ1\|\mu\| \leq 1 and μ^(G^){an:nN}{0}\widehat{\mu}(\widehat{G})\subset \{a_n: n \in \mathbb{N}\}\cup\{0\}, the measure μμ\mu\ast\mu is absolutely continuous with respect to Haar measure on GG. This implies that μ\mu does not exhibit the so-called Wiener-Pitt phenomenon. The paper is a continuation of investigations started in \cite{ow}.

Keywords

Cite

@article{arxiv.2510.24578,
  title  = {Wiener-Pitt sets for compact Abelian groups},
  author = {Przemysław Ohrysko and Tom Sanders and Michał Wojciechowski},
  journal= {arXiv preprint arXiv:2510.24578},
  year   = {2025}
}
R2 v1 2026-07-01T07:09:52.132Z