On the fiber product over infinite-genus Riemann surfaces

Considering non-constant holomorphic maps ${\beta }_i:S_i\to S_0$, $i\in \{1,2\}$, between non-compact Riemann surfaces for which it is associated its fiber product $S_1{\times }_{({\beta }_1,{\beta }_2)}{S}_2$. With this setting, in this paper we relate the ends space of such fiber product to the ends space of its normal fiber product. Moreover, we provide conditions on the maps ${\beta }_1$ and ${\beta }_2$ to guarantee connectednes on the fiber product. From these conditions, we link the ends space of fiber product with the topological type of the Riemann surfaces $S_1$ and $S_2$. We also study the fiber product over infinite hyperelliptic curves and discuss its connectedness and ends space.