English

A Generalization of Fermat's Principle for Classical and Quantum Systems

Quantum Physics 2014-10-14 v4

Abstract

The analogy between dynamics and optics had a great influence on the development of the foundations of classical and quantum mechanics. We take this analogy one step further and investigate the validity of Fermat's principle in many-dimensional spaces describing dynamical systems (i.e., the quantum Hilbert space and the classical phase and configuration space). We propose that if the notion of a metric distance is well defined in that space and the velocity of the representative point of the system is an invariant of motion, then a generalized version of Fermat's principle will hold. We substantiate this conjecture for time-independent quantum systems and for a classical system consisting of coupled harmonic oscillators. An exception to this principle is the configuration space of a charged particle in a constant magnetic field; in this case the principle is valid in a frame rotating by half the Larmor frequency, not the stationary lab frame.

Keywords

Cite

@article{arxiv.1302.7185,
  title  = {A Generalization of Fermat's Principle for Classical and Quantum Systems},
  author = {Tarek A. Elsayed},
  journal= {arXiv preprint arXiv:1302.7185},
  year   = {2014}
}

Comments

Revised edition; accepted for publication in Physics Letters A

R2 v1 2026-06-21T23:34:22.861Z