Positivity of anticanonical divisors in algebraic fibre spaces

Chi-Kang Chang

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arXiv · 2011.11561

Positivity of anticanonical divisors in algebraic fibre spaces

Chi-Kang Chang

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Abstract

Let $f:X\rightarrow Y$ be an algebraic fibre space between normal projective varieties and $F$ be a general fibre of $f$. We prove an Iitaka-type inequality $\kappa(X,-K_X)\leq \kappa(F,-K_F)+\kappa(Y,-K_Y)$ under some mild conditions. We also obtain some more results relates the positivity of $-K_X$ and $-K_Y$.

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Chi-Kang Chang. 2020-11-23. Positivity of anticanonical divisors in algebraic fibre spaces. https://arxiv.org/abs/2011.11561

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