English

A commutative algebraic approach to the fitting problem

Commutative Algebra 2012-04-09 v1 Optimization and Control

Abstract

Given a finite set of points Γ\Gamma in Pk1\mathbb P^{k-1} not all contained in a hyperplane, the "fitting problem" asks what is the maximum number hyp(Γ)hyp(\Gamma) of these points that can fit in some hyperplane and what is (are) the equation(s) of such hyperplane(s). If Γ\Gamma has the property that any k1k-1 of its points span a hyperplane, then hyp(Γ)=nil(I)+k2hyp(\Gamma)=nil(I)+k-2, where nil(I)nil(I) is the index of nilpotency of an ideal constructed from the homogeneous coordinates of the points of Γ\Gamma. Note that in P2\mathbb P^2 any two points span a line, and we find that the maximum number of collinear points of any given set of points ΓP2\Gamma\subset\mathbb P^2 equals the index of nilpotency of the corresponding ideal, plus one.

Keywords

Cite

@article{arxiv.1204.1390,
  title  = {A commutative algebraic approach to the fitting problem},
  author = {Stefan O. Tohaneanu},
  journal= {arXiv preprint arXiv:1204.1390},
  year   = {2012}
}

Comments

8 pages

R2 v1 2026-06-21T20:45:34.207Z