English

On the notion of canonical dimension for algebraic groups

Algebraic Geometry 2009-07-06 v2 Group Theory

Abstract

We define and study a new numerical invariant of an algebraic group action which we call the canonical dimension. We then apply the resulting theory to the problem of computing the minimal number of parameters required to define a generic hypersurface of degree d in P^{n-1}.

Keywords

Cite

@article{arxiv.math/0404391,
  title  = {On the notion of canonical dimension for algebraic groups},
  author = {G. Berhuy and Z. Reichstein},
  journal= {arXiv preprint arXiv:math/0404391},
  year   = {2009}
}

Comments

Significantly strenghtened, compared to the earlier version. To appear in Advances in Mathematics, 41 pages