The Time-Dependent Schrödinger Equation, Riccati Equation, and Airy Functions

Abstract

We construct the Green functions (or Feynman’s propagators) for the Schrödinger equations of the form iψt+14ψxx±tx2ψ=0 (for the wave function ψ and its time (t) and x-space derivatives) in terms of Airy functions and solve the Cauchy initial value problem in the coordinate and momentum representations. Particular solutions of the corresponding nonlinear Schrödinger equations with variable coefficients are also found. A special case of the quantum parametric oscillator is studied in detail first. The Green function is explicitly given in terms of Airy functions and the corresponding transition amplitudes are found in terms of a hypergeometric function. The general case of the quantum parametric oscillator is considered then in a similar fashion. A group theoretical meaning of the transition amplitudes and their relation with Bargmann’s functions is established. The relevant bibliography, to the best of our knowledge, is addressed.

Keywords

• time-dependent Schrödinger equation
• Airy functions
• Riccati equation
• Green’s functions
• quantum parametric oscillator
• <i>SU</i>(1,1) symmetry