Which causality? Differences between the trajectory and Copenhagen analyses of an impulsive perturbation

Abstract

The trajectory and Copenhagen representations render different predictions for impulse perturbations. The different predictions are due to the different roles that causality plays in the trajectory and Copenhagen interpretations. We investigate a small perturbing impulse acting on the ground state of an infinitely deep square well. For the two representations, the first-order perturbation calculations for the temporal change in energy differ. This temporal change in energy for the trajectory representation is dependent upon the microstate of the wave function. We show that even under Copenhagen epistemology, the two representations predict different theoretical results.