This article is cited in
1 paper
Polynomials, orthogonal on grids from unit circle and number axis
I. I. Sharapudinovab a Daghestan Scientific Centre of Russian Academy of Sciences, Makhachkala
b Vladikavkaz Scientific Centre of the Russian Academy of Sciences
Abstract:
In current paper we investigate the asymptotic properties of polynomials, orthogonal on arbitrary (not necessarily uniform) grids from an unit circle or segment
$[-1,1]$. When the grid of nodes $\Omega_N^T=\left\{e^{i\theta_0},e^{i\theta_1},\ldots,e^{i\theta_{N-1}}\right\}$ belongs to the unit circle
$|w|=1$ we consider polynomials
$\varphi_{0,N}(w),\varphi_{1,N}(w),\ldots,$ $\varphi_{N-1,N}(w)$, orthogonal in the following sense:
$$
\frac1{2\pi}\int\limits_{-\pi}^\pi
\varphi_{n,N}(e^{i\theta})\overline{\varphi_{m,N}(e^{i\theta})}\,d\sigma_N(\theta)=
$$
$$
\frac1{2\pi}\sum\limits^{N-1}_{j=0}
\varphi_{n,N}(e^{i\theta_j})\overline{\varphi_{m,N}(e^{i\theta_j})}
\Delta\sigma_N(\theta_j)=\delta_{nm},
$$
where $\Delta\sigma_N(\theta_j)=\sigma_N(\theta_{j+1})-\sigma_N(\theta_j),
j=0,\ldots,N-1$. In case, when $\Delta\sigma_N(\theta_j)=h(\theta_j)\Delta\theta_j$, the asymptotic formula for
$\varphi_{n,N}(w)$ is established, which in turn, used for investigation of asymptotic properties of polynomials which are orthogonal on grids from
$[-1,1]$.
Keywords:
unit circle, number axis, polynomials orthogonal on grids, asymptotic formulas.
UDC:
517.538 Received: 25.10.2013
Revised: 15.04.2014
Accepted: 17.04.2014
DOI:
10.31029/demr.1.1