Limits of definable families and dilations in nilmanifolds

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Peterzil, Ya'acov, Starchenko, Sergei
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917707361812480
author Peterzil, Ya'acov
Starchenko, Sergei
author_facet Peterzil, Ya'acov
Starchenko, Sergei
contents Let $G$ be a unipotent group and $\mathcal F=\{F_t:t\in (0,\infty)\}$ a family of subsets of $G$, with $\mathcal F$ definable in an o-minimal expansion of the real field. Given a lattice $Γ\subseteq G$, we study the possible Hausdorff limits of $π(\mathcal F)$ in $G/Γ$ as $t$ tends to $\infty$ (here $π:G\to G/Γ$ is the canonical projection). Towards a solution, we associate to $\mathcal F$ finitely many real algebraic subgroups $L\subseteq G$, and, uniformly in $Γ$, determine if the only Hausdorff limit at $\infty$ is $G/Γ$, depending on whether $L^Γ=G$ or not. The special case of polynomial dilations of a definable set is treated in details.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19160
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Limits of definable families and dilations in nilmanifolds
Peterzil, Ya'acov
Starchenko, Sergei
Logic
Dynamical Systems
Let $G$ be a unipotent group and $\mathcal F=\{F_t:t\in (0,\infty)\}$ a family of subsets of $G$, with $\mathcal F$ definable in an o-minimal expansion of the real field. Given a lattice $Γ\subseteq G$, we study the possible Hausdorff limits of $π(\mathcal F)$ in $G/Γ$ as $t$ tends to $\infty$ (here $π:G\to G/Γ$ is the canonical projection). Towards a solution, we associate to $\mathcal F$ finitely many real algebraic subgroups $L\subseteq G$, and, uniformly in $Γ$, determine if the only Hausdorff limit at $\infty$ is $G/Γ$, depending on whether $L^Γ=G$ or not. The special case of polynomial dilations of a definable set is treated in details.
title Limits of definable families and dilations in nilmanifolds
topic Logic
Dynamical Systems
url https://arxiv.org/abs/2406.19160