English

Birational modifications of surfaces via unprojections

Algebraic Geometry 2010-03-23 v2 Commutative Algebra

Abstract

We describe elementary transformations between minimal models of rational surfaces in terms of unprojections. These do not fit into the framework of Kustin-Miller unprojections as introduced by Papadakis and Reid, since we have to leave the world of projectively Gorenstein varieties. Also, our unprojections do not depend on the choice of the unprojection locus only, but need extra data corresponding to the choice of a divisor on this unprojection locus.

Keywords

Cite

@article{arxiv.0904.4204,
  title  = {Birational modifications of surfaces via unprojections},
  author = {Christian Liedtke and Stavros Argyrios Papadakis},
  journal= {arXiv preprint arXiv:0904.4204},
  year   = {2010}
}

Comments

12 pages, only minor changes

R2 v1 2026-06-21T12:55:28.347Z