Scattering problem for the Schrödinger equation in the case of a potential linear in time and coordinate. I. Asymptotics in the shadow zone

The formal asymptotics of the scattering problem for the Schrödinger equation with a linear potential as $x+|t|\to+\infty$ is studied. In the shadow zone a formal asymptotic expansion is constructed which is matched with the known asymptotics as $t\to-\infty$. The expansion constructed loses asymptotic character near the curve $x=\frac16t^3$ (in the so-called projector zone). An assumption regarding the analogous behavior of the asymptotic series in the projector zone makes it possible to construct an expansion in the post-projection zone which goes over into the formulas for creeping waves.