English

On the birationality of the adjunction mapping of projective varieties

Algebraic Geometry 2011-09-13 v1

Abstract

Let XX be a smooth projective nn-fold such that q(X)=0q(X)=0 and LL a globally generated, big line bundle on XX such that h0(KX+(n2)L)>0h^0(K_X+(n-2)L) >0. We give necessary and sufficient conditions for the adjoint systems KX+kL|K_X+kL| to be birational for kn1k \geq n-1. In particular, for Calabi-Yau nn-folds we generalize and prove parts of a conjecture of Gallego and Purnaprajna.

Keywords

Cite

@article{arxiv.1109.2439,
  title  = {On the birationality of the adjunction mapping of projective varieties},
  author = {Andreas Leopold Knutsen},
  journal= {arXiv preprint arXiv:1109.2439},
  year   = {2011}
}

Comments

7 pages, accepted for publication in Journal of the Ramanujan Mathematical Society