English

Threefold extremal contractions of type IA

Algebraic Geometry 2011-07-07 v1

Abstract

Let (X,C)(X,C) be a germ of a threefold XX with terminal singularities along an irreducible reduced complete curve CC with a contraction f:(X,C)(Z,o)f: (X,C)\to (Z,o) such that C=f^{-1}(o)_{\red} and KX-K_X is ample. Assume that a general member FKXF\in |-K_X| meets CC only at one point PP and furthermore (F,P)(F,P) is Du Val of type A if index(X,P)=4(X,P)=4. We classify all such germs in terms of a general member HOXH\in |O_X| containing CC.

Keywords

Cite

@article{arxiv.1004.4188,
  title  = {Threefold extremal contractions of type IA},
  author = {Shigefumi Mori and Yuri Prokhorov},
  journal= {arXiv preprint arXiv:1004.4188},
  year   = {2011}
}

Comments

LaTeX, 37 pages