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arXiv · 1212.5075

Fano-Mori contractions of high length on projective varieties with terminal singularities

Marco Andreatta·Luca Tasin
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Abstract

Let X be a projective variety with terminal singularities and let L be an ample Cartier divisor on X. We prove that if f is a birational contraction associated to an extremal ray $ R \subset \bar {NE(X)}$ such that R.(K_X+(n-2)L)<0, then f is a weighted blow-up of a smooth point. We then classify divisorial contractions associated to extremal rays R such that R.(K_X+rL)<0, where r is a non-negative rational number, and the fibres of f have dimension less or equal to r+1.

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Marco Andreatta, Luca Tasin. 2012-12-20. Fano-Mori contractions of high length on projective varieties with terminal singularities. https://doi.org/10.1112/blms%2Fbdt083

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