Alternative algebraic techniques to approximate a given Hamiltonian by a harmonic oscillator are described both for timeindependent and time-dependent systems. We apply them to the description of a one-dimensional atom-diatom collision. From the resulting evolution operator, we evaluate vibrational
Analytic approximation to the harmonic oscillator equation with a sub-period time dependent parameter
✍ Scribed by M. Fernández Guasti
- Publisher
- Elsevier Science
- Year
- 2004
- Tongue
- English
- Weight
- 135 KB
- Volume
- 189
- Category
- Article
- ISSN
- 0167-2789
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✦ Synopsis
Analytic solutions are presented for the time dependent harmonic oscillator equation as well as for the corresponding amplitude (Ermakov) and phase equations. The solutions are adequate approximations for an initially constant amplitude and a time dependent parameter that varies continuously in a time much shorter than the characteristic period. The amplitude and phase representation of the solution is shown not to be unique. The relationship between the phase independent amplitudes is derived from the orthogonal functions invariant.
📜 SIMILAR VOLUMES
The solution to Newton's second law for a harmonic oscillator with a time-dependent force constant allows the solutions to the corresponding time-dependent Schkidinger equation to be written down by analogy.
a b s t r a c t I discuss the problem of time-dependent harmonic oscillators on the basis of a periodic functional approach to the calculus of variations. Both the Lagrangian and Hamiltonian formulations are explored and discussed in some detail. Some interesting consequences are revealed.