English

On a notion of speciality of linear systems in P^n

Algebraic Geometry 2015-10-01 v2 Commutative Algebra

Abstract

Given a linear system in P^n with assigned multiple general points we compute the cohomology groups of its strict transforms via the blow-up of its linear base locus. This leads us to give a new definition of expected dimension of a linear system, which takes into account the contribution of the linear base locus, and thus to introduce the notion of linear speciality. We investigate such a notion giving sufficient conditions for a linear system to be linearly non-special for arbitrary number of points, and necessary conditions for small numbers of points.

Keywords

Cite

@article{arxiv.1210.5175,
  title  = {On a notion of speciality of linear systems in P^n},
  author = {Maria Chiara Brambilla and Olivia Dumitrescu and Elisa Postinghel},
  journal= {arXiv preprint arXiv:1210.5175},
  year   = {2015}
}

Comments

26 pages. Minor changes, Definition 3.2 slightly extended. Accepted for publication in Transactions of AMS