Exact discretization of Schrodinger equation

There are different approaches to discretization of the Schrodinger equation with some approximations. In this paper we derive a discrete equation that can be considered as exact discretization of the continuous Schredinger equation. The proposed discrete equation is an equation with difference of integer order that is represented by infinite series. We suggest differences, which are characterized by power-law Fourier transforms. These differences can be considered as exact discrete analogs of derivatives of integer orders. Physically the suggested discrete equation describes a chain (or lattice) model with long-range interaction of power-law form. Mathematically it is a uniquely highlighted difference equation that exactly corresponds to the continuous Schrodinger equation. Using the Young's inequality for convolution, we prove that suggested differences are operators on the Hilbert space of square-summable sequences. We prove that the wave functions, which are exact discrete analogs of the free particle and harmonic oscillator solutions of the continuous Schrodinger equations, are solutions of the suggested discrete Schrodinger equations. (C) 2015 Elsevier B.V. All rights reserved.