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arXiv · 1202.1154

On the Picard number of singular Fano varieties

Gloria Della Noce
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Abstract

Let X be a Q-factorial Gorenstein Fano variety. Suppose that the singularities of X are canonical and that the locus where they are non-terminal has dimension zero. Let D be a prime divisor of X. We show that rho_X - rho_D < 9 (where rho is the Picard number). Moreover, if rho_X - rho_D > 3, there exists a finite morphism from X to S x Y, where S is a surface with rho_S at most 9. As an application we prove that, if X has dimension 3, then rho_X is at most 10.

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Gloria Della Noce. 2012-02-06. On the Picard number of singular Fano varieties. https://doi.org/10.1093/imrn%2Frns236

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