Autohomeomorphisms of the finite powers of the double arrow

Abstract

Let $\mathbb{A}$ and $\mathbb{S}$ denote the double arrow of Alexandroff and the Sorgenfrey line, respectively. We show that any homeomorphism $h:^m\mathbb{A}\to^m\mathbb{A} $ is locally (outside of a nowhere dense set) a product of monotone embeddings $h_i:J_i\subseteq \mathbb{A}\to\mathbb{A} (i\in m)$ followed by a permutation of the coordinates. We also prove that the symmetric products $\mathcal{F}_m(\mathbb{A})$ are not homogeneous for any $m\geq 2$. This partially solves an open question of A. Arhangel'ski\v{i}. In contrast, we show that symmetric product $\mathcal{F}_2(\mathbb{S})$ is homogeneous.