On a classification of irreducible periodic diffeomorphisms on surfaces which commute with certain involution
Norihisa Takahashi, Hiraku Nozawa
TL;DR
The paper addresses the problem of classifying irreducible periodic diffeomorphisms on a genus $g$ surface that commute with an involution $\iota_g$ whose quotient is a torus $T^2$. It develops a framework based on total valency (Nielsen data) and leverages Riemann–Hurwitz, Harvey’s criterion for cyclic coverings, and torus-quotient dynamics to constrain possible lifts. The authors obtain a finite list of conjugacy classes for such irreducible actions, realized by specific generators $h_{n,p}$ (e.g., $h_{6,1}$, $h_{8,1}$, $h_{8,5}$, $h_{12,2}$, $h_{12,3}$) up to conjugacy, and prove the nonexistence of irreducible roots for certain constructed examples $F_1$ and $F_2$. This sharpens the understanding of symmetry groups of surfaces with torus quotients and highlights a marked contrast with Ishizaka’s hyperelliptic (sphere-quotient) classification, by yielding a finite, explicit catalog of possibilities.
Abstract
Ishizaka classified up to conjugacy hyperelliptic periodic automorphisms of a surface. Here, an involution $I$ on a surface $Σ_{g}$ is hyperelliptic if and only if $Σ_{g}/\langle I \rangle$ is homeomorphic to $S^2$. In this article, we give a classification up to conjugacy for irreducible periodic automorphisms of a surface $Σ_{g}$ which commute with involutions $ι$ such that $Σ_{g}/\langle ι\rangle$ is homeomorphic to $T^{2}$.
