Kodaira additivity, birational isotriviality and specialness

We show, using [14], that a smooth projective fibration f : X → Y between connected complex quasi-projective manifolds satisfies the equality κ(X) = κ(X y) + κ(Y) of Logarithmic Kodaira dimensions if its fibres X y admit a good minimal model. Without the last assumption, this was conjectured in [11]. Several cases are established in [13], which inspired the present text. Although the present results overlap with those of [13] in the projective case, the approach here is different, based on the rôle played by birationally isotrivial fibrations, special manifolds and the core map of Y introduced and constructed in [3]