Skip to content

The Importance of Boundary Conditions in Quantum Mechanics

R. de la Madrid

quant-pharXiv:quant-ph/0302184

Abstract

We discuss the role of boundary conditions in determining the physical content of the solutions of the Schrodinger equation. We study the standing-wave, the ``in,'' the ``out,'' and the purely outgoing boundary conditions. As well, we rephrase Feynman's +i ε prescription as a time-asymmetric, causal boundary condition, and discuss the connection of Feynman's +i ε prescription with the arrow of time of Quantum Electrodynamics. A parallel of this arrow of time with that of Classical Electrodynamics is made. We conclude that in general, the time evolution of a closed quantum system has indeed an arrow of time built into the propagators.

Create a lesson