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arXiv · 2309.16580

On the superadditivity of anticanonical Iitaka dimension

Marta Benozzo·Iacopo Brivio·Chi-Kang Chang
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Abstract

Given a fibration $f: X \to Y$ with normal general fibre $X_y$, over a field of any characteristic, we establish the Iitaka-type inequality $\kappa(X,-K_X) \leq \kappa(X_y,-K_{X_y})+\kappa(Y,-K_Y)$ whenever the $\mathbb{Q}$-linear series $|-K_X|_{\mathbb{Q}}$ has good singularities on $X_y$.

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Marta Benozzo, Iacopo Brivio, Chi-Kang Chang. 2023-09-28. On the superadditivity of anticanonical Iitaka dimension. https://doi.org/10.1016/j.aim.2026.110860

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