Problems / geometry-topology
geometry-topology / Birational geometry, Kodaira dimension of smooth families
Popa's logarithmic additivity conjecture for log-smooth families
Theorem 1.1: under Popa's hypotheses (reduced SNC E, D, support inclusion, stratum smoothness over V), κ(X,KX+E)≤κ(Y,KY+D)+κ(F,KF+EF), and if either term on the right is −∞ every H0(X,m(KX+E)) vanishes; no abundance or good-model hypothesis. With the family's logarithmic subadditivity this gives equality, Corollary 1.2. Either divisor may be zero, which covers additivity for smooth projective morphisms; the paper itself claims only Conjecture 3.9. Not covered: families that are not log-smooth over the open base.