Random polynomials having few or no real zeros

نویسندگان

  • Amir Dembo
  • Bjorn Poonen
چکیده

Consider a polynomial of large degree n whose coefficients are independent, identically distributed, non-degenerate random variables having zero mean and finite moments of all orders. We show that such a polynomial has exactly k real zeros with probability n−b+o(1) as n → ∞ through integers of the same parity as the fixed integer k ≥ 0. In particular, the probability that a random polynomial of large even degree n has no real zeros is n−b+o(1). The finite, positive constant b is characterized via the centered, stationary Gaussian process of correlation function sech(t/2). The value of b depends neither on k nor upon the specific law of the coefficients. Under an extra smoothness assumption about the law of the coefficients, with probability n−b+o(1) one may specify also the approximate locations of the k zeros on the real line. The constant b is replaced by b/2 in case the i.i.d. coefficients have a nonzero mean.

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تاریخ انتشار 2000