Editing Particle in a box (section)

=== More complicated wall shapes ===

The wave function for a quantum-mechanical particle in a box whose walls have arbitrary shape is given by the [[Helmholtz equation]] subject to the boundary condition that the wave function vanishes at the walls. These systems are studied in the field of [[quantum chaos]] for wall shapes whose corresponding [[dynamical billiards|dynamical billiard tables]] are non-integrable.