English

The Protasov-Zelenyuk topology and ideal convergence

Group Theory 2025-12-04 v1 General Topology

Abstract

The so-called TT-sequences u\mathbf u in a group GG, and the related finest Hausdorff group topology TuT_\mathbf u on GG that makes u\mathbf u a null sequence, were introduced by Protasov and Zelenyuk 35 years ago and since then they became a fundamental tool in the field of topological groups. More recently, in the abelian case, the subfamily of TT-sequences called TBTB-sequences was introduced, as well as the finest precompact group topology TpuT_\mathbf{pu} that makes u\mathbf u a null sequence. Here we study the counterpart of all these notions with respect to ideal convergence in place of the classical notion of convergence of a sequence. Also, we study their relation to the already established field of II-characterized subgroups of compact abelian groups.

Keywords

Cite

@article{arxiv.2512.03885,
  title  = {The Protasov-Zelenyuk topology and ideal convergence},
  author = {Lydia Außenhofer and Dikran Dikranjan and Anna Giordano Bruno},
  journal= {arXiv preprint arXiv:2512.03885},
  year   = {2025}
}