On uniqueness of automorphisms groups of Riemann surfaces

Abstract

Let $\gamma ,r,s$, $\ge 1$ be non-negative integers. If $p$ is a prime sufficiently large relative to the values $\gamma$, $r$ and $s$, then a group $H$ of conformal automorphisms of a closed Riemann surface $S$ of order $p^s$ so that $S/H$ has signature $(\gamma ,r)$ is the unique such subgroup in $\mathrm{Aut}(S)$. Explicit sharp lower bounds for $p$ in the case $(\gamma ,r,s)\in \{(1,2,1),(0,4,1)\}$ are provided. Some consequences are also derived.