On uniform convergence of spectral expansions and their derivatives
corresponding to self-adjoint extensions of Schrödinger operator
Nebojša L. Lažetić
Abstract
In this paper we consider problem of the global uniform
convergence of spectral expansions and their derivatives generated by arbitrary
non-negative self-adjoint extensions of the Schrödinger operator
$$
\Cal L(u)(x)=-u^{\prime\prime}(x)+q(x)u(x) \tag 1
$$
with discrete spectrum, for functions in the Sobolev class
$\overset\circ\to{W}_p^{(k)}(G)$
($p>1$) defined on a finite interval $G\subset R$.
Assuming that the potential $q(x)$ of the operator $\Cal L$ belongs to
the class $L_p(G)$ ($1