Almost Regular Coverings of the Sphere: Realizability. I. Tetrahedral Case

Nikolai M. Adrianov, Elena M. Kreines

We prove the realizability of genus-$0$ branch data of the form $(2^r,a|3^s,b|3^t,c)$ and $(2^r,a|3^s|3^t,b,c)$, where $a$, $b$, $c$ are…