Author/Authors :
Rezakhah، S. نويسنده , , Soltani، A.R نويسنده Department of Statistics, Shiraz University (and Kuwait University) Shiraz, P.O. Box 5969 Safat 13060, Iran ,
Abstract :
Let
$ P_{n}(x)= \sum_{i=0}^{n} A_{i}x^{i}$ be a random algebraic
polynomial,
where $A_{0},A_{1}, \ldots $ is a sequence of independent
random variables belong to the domain of attraction of the normal law.
Thus
$A_j$ʹs for $j=0,1,\ldots $
possess the characteristic functions $\exp \{
-\frac{1}{2}t^{2}H_{j}(t)\}$, where $H_j(t)$ʹs are complex slowly
varying functions.
Under the assumption that there exist a real positive slowly varying function $H(\cdot)$ and positive constants $t_{0}$, $ C_{\ast}$ and
$C^{\ast}$ that $C_{\ast} H(t) \leq \mbox{Re}[H_{j}(t)] \leq C^{\ast} H(t),\;t\leq
t_{0},\;j=1,\ldots,n$, we find that while the variance of coefficients are bounded, real zeros are concentrated around $\pm 1$, and
the expected number of real zeros of $P_n(x)$ round the origin at a distance $(\log n)^{-s}$ of $\pm 1$ are at most of order
$O\left( (\log n)^s \log (\log n)\right)$.