English

Remarks on Type III Unprojection

Algebraic Geometry 2007-05-23 v1 Commutative Algebra

Abstract

Type III unprojection plays a very important role in the birational geometry of Fano threefolds. It was first introduced by A. Corti on his calculations of Fano threefolds of genus 6 and 7. It seems that at present a general definition of the type III unprojection is still missing. After proving some general facts about residual ideals, we propose a definition for the generic Type III unprojection, and prove that it gives a Gorenstein ring.

Cite

@article{arxiv.math/0501535,
  title  = {Remarks on Type III Unprojection},
  author = {Stavros Argyrios Papadakis},
  journal= {arXiv preprint arXiv:math/0501535},
  year   = {2007}
}

Comments

11 pages, to appear in Communications in Algebra