## Lie theory and separation of variables. 6. The equation iUt + ∆2U = 0

##### Citation

Boyer, C.P., Kalnins, E.G. & Miller, W., Jr. (1975). Lie theory and separation of variables. 6. The equation iUt + ∆2U = 0. Journal of Mathematical Physics, 16, 499.

Permanent Research Commons link: http://hdl.handle.net/10289/1244

##### Abstract

This paper constitutes a detailed study of the nine−parameter symmetry group of the time−dependent free particle Schrödinger equation in two space dimensions. It is shown that this equation separates in exactly 26 coordinate systems and that each system corresponds to an orbit consisting of a commuting pair of first− and second−order symmetry operators. The study yields a unified treatment of the (attractive and repulsive) harmonic oscillator, linear potential and free particle Hamiltonians in a time−dependent formalism. Use of representation theory for the symmetry group permits simple derivations of addition and expansion theorems relating various solutions of the Schrödinger equation, many of which are new.

##### Date

1975-03##### Type

##### Rights

Copyright 1975 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in the Journal of Mathematical Physics and may be found at http://jmp.aip.org/jmp/top.jsp