Year: 2026
Type: preprint
Abstract: The Borel distinguishing number $D_B(\mathcal{G})$ of a Borel graph $\mathcal{G}$, recently introduced by Bilge and Kaya, is the minimum number of colors required to break the symmetry of $\mathcal{G}$ in a Borel way. In this paper, we investigate the Borel distinguishing number of Schreier graphs induced by the free part of the shift action $Γ\curvearrowright n^Γ$. We prove that $D_B(\mathcal{G})\le n+1$ for $Γ=\mathbb{Z}^d$ equipped with the standard generators. Moreover, we show that $D_B(\mathcal{G})\ge n+1$ if $ Γ$ is amenable and $ \{γ\in \mathrm{Aut}(\mathrm{Cay}(Γ,S)) \mid γ(e) = e \}$ is non-trivial. We also show that $D_B(\mathcal{G})$ is finite if $Γ$ is finitely generated, and give some applications of our results. These results answer some questions raised by Bilge and Kaya.
Source: arXiv (Cornell University)
Authors: Chen, Junhao, Zou, Jie
Language: English
Subfield: Computational Theory and Mathematics
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7213292561