The group of boundary fixing homeomorphisms of the disc is not left-orderable


A left-order on a group $G$ is a total order $\lt $ on $G$ such that for any $f$, $g$ and $h$ in $G$ we have $f < g \Leftrightarrow hf < hg$. We construct a finitely generated subgroup $H$ of $\mathrm {Homeo} (I^2;\delta I^2)$, the group of those homeomorphisms of the disc that fix the boundary pointwise, and show $H$ does not admit a left-order. Since any left-order on $\mathrm {Homeo} (I^2;\delta I^2)$ would restrict to a left-order on $H$, this shows that $\mathrm {Homeo} (I^2;\delta I^2)$ does not admit a left-order. Since $\mathrm {Homeo}(I;\delta I)$ admits a left-order, it follows that neither $H$ nor $\mathrm {Homeo} (I^2;\delta I^2)$ embed in $\mathrm {Homeo}(I;\delta I)$.


James Hyde

Cornell University, Ithaca, NY