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On Classification of the extremal contraction from a smooth fourfold

Hiromichi Takagi
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Abstract

We classify extremal divisorial contraction which contracts a divisor to a curve from a smooth fourfold. We prove the exceptional divisor is $\Bbb P^2$bundle or quadric bundle over a smooth curve and the contraction is the blowing up along the curve.

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Hiromichi Takagi. 1996-04-19. On Classification of the extremal contraction from a smooth fourfold. https://arxiv.org/abs/alg-geom/9604013

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