2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162535Consider the solution of the time-dependent Schr{ö}dinger equation with initial data $f$. It is shown in \cite{artikel} that there exists $f$ in the Sobolev space $H^s(\RR), s=n/2$ such that tangential convergence can not be widened to convergence regions. In this paper we show that the corresponding result holds when $-Δ_x$ is replaced by an operator $ϕ(D)$, with special conditions on $ϕ$.Analysis of PDEstext