English

On the Number of Real Zeros of Random Fewnomials

Probability 2019-12-24 v4

Abstract

Consider a system f1(x)=0,,fn(x)=0f_1(x)=0,\ldots,f_n(x)=0 of nn random real polynomials in nn variables, where each fif_i has a prescribed set of terms described by a set ANnA\subseteq \mathbb{N}^n of cardinality tt. Assuming that the coefficients of the fif_i are independent Gaussians of any variance, we prove that the expected number of zeros of the random system in the positive orthant is bounded from above by 12n1(tn)\frac{1}{2^{n-1}}\binom{t}{n}.

Keywords

Cite

@article{arxiv.1811.09425,
  title  = {On the Number of Real Zeros of Random Fewnomials},
  author = {Peter Bürgisser and Alperen A. Ergür and Josué Tonelli-Cueto},
  journal= {arXiv preprint arXiv:1811.09425},
  year   = {2019}
}

Comments

9 pages. 2nd version: Fixed an error in the proof of Corollary 2.2, which led to changes in some of the constants. Added a missing reference. Added proof of better bound for the univariate case. 3rd version: Improvement of the statement of the main theorem