Search results for "finite coverings"

MR 2831984 Reviewed Masuda T. Families of finite coverings of the Riemann sphere. Osaka J. Math. 48 (2011), no. 2, 515--540. (Reviewer Francesca Vetr…

2012

Let $G$ be a finite group and let $H$ be a subgroup of $G$ which does not contain normal subgroups of $G$ except $\{ id \}$. The group $G$ acts on the set of the left coset of $G / H$ as follows: \begin{center} $(g, H a) \rightarrow H a g^{- 1}$. \end{center} The author observes that the action defined above is effective and this gives a permutation representation of $G$, $R: G \rightarrow S_{d}$, where $d =[G : H]$. The condition on $H$ ensures that $R$ is injective. Thus, $G$ can be seen as a transitive subgroup of $S_{d}$. Let $X$ and $ Y$ be connected complex varieties. A finite covering $f: X \rightarrow Y$, which branches at most at $B$, is said a $(G, H)-$coverings if there is a surj…