Abstract
We consider random polynomials whose coefficients are independent and uniform on {-1, 1}. We prove that the probability that such a polynomial of degree n has a double root is o(n-2) when n+1 is not divisible by 4 and asymptotic to 1/\sqrt 3 otherwise. This result is a corollary of a more general theorem that we prove concerning random polynomials with independent, identically distributed coefficients having a distribution which is supported on {-1, 0, 1} and whose largest atom is strictly less than \frac{{8\sqrt 3 }}{{\pi {n^2}}}. In this general case, we prove that the probability of having a double root equals the probability that either -1, 0 or 1 are double roots up to an o(n-2) factor and we find the asymptotics of the latter probability.
Original language | English |
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Pages (from-to) | 55-77 |
Number of pages | 23 |
Journal | Israel Journal of Mathematics |
Volume | 213 |
Issue number | 1 |
DOIs | |
State | Published - 1 Jun 2016 |
All Science Journal Classification (ASJC) codes
- General Mathematics