Eckart Viehweg And

Example 0.1. Let f : X → P be a non-isotrivial semistable family of Abelian varieties of dimension g over the complex line, then: i. s = #{ singular fibres } ≥ 4. ii. s = 4 if and only if f is isogenous to E ×P1 E ×P1 · · · ×P1 E where E → P is one of the 6 modular families of elliptic curves, smooth over P \ {y1, . . . , y4} for some distinct points y1, . . . , y4 ∈ P (as described in [Beauville 82]).