Classification of extremal contractions

from smooth fourfolds of -type

Author:
Hiromichi Takagi

Journal:
Proc. Amer. Math. Soc. **127** (1999), 315-321

MSC (1991):
Primary 14E30; Secondary 14J35

DOI:
https://doi.org/10.1090/S0002-9939-99-05114-X

MathSciNet review:
1637436

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Abstract | References | Similar Articles | Additional Information

Abstract: We investigate divisorial contractions of extremal rays from

smooth fourfolds. When the exceptional divisor is contracted to a curve, we prove that the divisor is a -bundle or quadric bundle over a smooth curve and the contraction is the blowing up along the curve. Furthermore we determine the local analytic structure of the contraction.

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Additional Information

**Hiromichi Takagi**

Affiliation:
Department of Mathematical Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-0041, Japan

Email:
htakagi@ms.u-tokyo.ac.jp

DOI:
https://doi.org/10.1090/S0002-9939-99-05114-X

Keywords:
Extremal ray,
contraction morphism

Received by editor(s):
February 12, 1997

Received by editor(s) in revised form:
April 24, 1997

Additional Notes:
The author is a Research Fellow of the Japan Society for the Promotion of Science

Communicated by:
Ron Donagi

Article copyright:
© Copyright 1999
American Mathematical Society