English

Intrinsic uniform structure on median algebras

General Topology 2026-05-18 v1 Dynamical Systems Functional Analysis

Abstract

We introduce the median uniformity Um\mathcal U_{\mathrm m}, an intrinsic precompact convex uniform structure on a median algebra. It is Hausdorff under natural assumptions, for instance for finite-rank median algebras. In the Hausdorff case, its uniform completion yields the Minimal Median Compactification (MMC). The induced topology τm\tau_{\mathrm m} provides a natural higher-rank analogue of the interval topology on linearly ordered sets and of the shadow topology on rank-one median algebras. When all intervals in the median algebra XX are finite, the MMC is the unique proper median compactification of (X,τm)(X,\tau_{\mathrm m}); in particular, it coincides with the Roller compactification. We apply this uniform framework to continuous actions of a topological group GG by median automorphisms. We show that the MMC is a median GG-compactification. In the finite-rank case, the resulting compact GG-system is Rosenthal representable and hence dynamically tame.

Keywords

Cite

@article{arxiv.2605.16096,
  title  = {Intrinsic uniform structure on median algebras},
  author = {Michael Megrelishvili},
  journal= {arXiv preprint arXiv:2605.16096},
  year   = {2026}
}

Comments

26 pages, 1 figure