English

Robust Sylvester-Gallai type theorem for quadratic polynomials

Computational Geometry 2022-02-11 v1 Computational Complexity

Abstract

In this work, we extend the robust version of the Sylvester-Gallai theorem, obtained by Barak, Dvir, Wigderson and Yehudayoff, and by Dvir, Saraf and Wigderson, to the case of quadratic polynomials. Specifically, we prove that if QC[x1.,xn]\mathcal{Q}\subset \mathbb{C}[x_1.\ldots,x_n] is a finite set, Q=m|\mathcal{Q}|=m, of irreducible quadratic polynomials that satisfy the following condition: There is δ>0\delta>0 such that for every QQQ\in\mathcal{Q} there are at least δm\delta m polynomials PQP\in \mathcal{Q} such that whenever QQ and PP vanish then so does a third polynomial in Q{Q,P}\mathcal{Q}\setminus\{Q,P\}, then dim(span(Q))=poly(1/δ)\dim(\text{span}({\mathcal{Q}}))=\text{poly}(1/\delta). The work of Barak et al. and Dvir et al. studied the case of linear polynomials and proved an upper bound of O(1/δ)O(1/\delta) on the dimension (in the first work an upper bound of O(1/δ2)O(1/\delta^2) was given, which was improved to O(1/δ)O(1/\delta) in the second work).

Keywords

Cite

@article{arxiv.2202.04932,
  title  = {Robust Sylvester-Gallai type theorem for quadratic polynomials},
  author = {Shir Peleg and Amir Shpilka},
  journal= {arXiv preprint arXiv:2202.04932},
  year   = {2022}
}

Comments

arXiv admin note: text overlap with arXiv:2006.08263

R2 v1 2026-06-24T09:29:45.972Z