Abstract:
In this paper we consider the system of polynomials
$l_{r,n}^{\alpha}(x)$ ($r$ — natural number, $n=0, 1,
\ldots$), orthonormal with respect to the Sobolev inner product
(Sobolev orthonormal polynomials) of the following type $\langle
f,g\rangle=\sum_{\nu=0}^{r-1}f^{(\nu)}(0)g^{(\nu)}(0)+\int_{0}^{\infty}
f^{(r)}(t)g^{(r)}(t)\rho(t)\,dt$ and generated by the classical
orthonormal Laguerre polynomials. Recurrence relations are
obtained for the system of Sobolev orthonormal polynomials, which
can be used for studying various properties of these polynomials
and calculate their values for any $x$ and $n$. Moreover, we
consider the system of the Laguerre functions $\mu_{n}^{\alpha}(x)
= \sqrt{\rho(x)}l_{n}^{\alpha}(x)$, which generates a system of
functions $\mu_{r, n}^{\alpha}(x)$ orthonormal with respect to the
inner product of the following form $\langle
\mu_{r,n}^\alpha,\mu_{r,k}^\alpha\rangle=
\sum_{\nu=0}^{r-1}(\mu_{r,n}^\alpha(x))^{(\nu)}|_{x=0}
(\mu_{r,k}^\alpha(x))^{(\nu)}|_{x=0}+ \int_{0}^{\infty}
(\mu_{r,n}^\alpha(x))^{(r)}(\mu_{r,k}^\alpha(x))^{(r)}\,dx.$ For
the generated system of functions $\mu_{r,n}^{\alpha}(x)$,
recurrence relations for $\alpha=0$ are also obtained.