A New Look at the Multidimensional Inverse Scattering Problem

TL;DR

This paper introduces a geometric method for solving the multidimensional inverse scattering problem for various quantum evolution equations, providing uniqueness, high-energy limits, and reconstruction formulas for potentials.

Contribution

It offers a novel geometric approach to inverse scattering, establishing uniqueness and explicit reconstruction formulas for potentials in multidimensional quantum systems.

Findings

Proved uniqueness of the potential from the scattering operator.

Derived explicit high-energy limits of the scattering operator.

Provided reconstruction formulas for the potential.

Abstract

As a prototype of an evolution equation we consider the Schr\"odinger equation i (d/dt) \Psi(t) = H \Psi(t), H = H_0 + V(x) for the Hilbert space valued function \Psi(.) which describes the state of the system at time t in space dimension at least 2. The kinetic energy operator H_0 may be propotional to the Laplacian (nonrelativistic quantum mechanics), H_0 = \sqrt{-\Delta + m^2} (relativistic kinematics, Klein-Gordon equation), the Dirac operator, or ..., while the potential V(x) tends to 0 suitably as |x| to infinity. We present a geometrical approach to the inverse scattering problem. For given scattering operator S we show uniqueness of the potential, we give explicit limits of the high-energy behavior of the scattering operator, and we give reconstruction formulas for the potential. Our mathematical proofs closely follow physical intuition. A key observation is that at high energies translation of wave packets dominates over spreading during the interaction time. Extensions of the method cover e.g. Schr\"odinger operators with magnetic fields, multiparticle systems, and wave equations.