On the superadditivity of anticanonical Iitaka dimension

2023/09/28 by Benozzo, Marta, Brivio, Iacopo, Chang, Chi-Kang
#14D06 #14G17 #14J17 #Algebraic Geometry (math.AG) #FOS: Mathematics

paper · doi:10.48550/arxiv.2309.16580

Abstract

Given a fibration f: X → Y with normal general fibre X_y, over a field of any characteristic, we establish the Iitaka-type inequality κ(X,-K_X) ≤ κ(X_y,-K_Xy)+κ(Y,-K_Y) whenever the ℚ-linear series |-K_X|_ℚ has good singularities on X_y.

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