Semiclassical Propagator: Explicit Formulation

This lecture delves into the semiclassical propagator, starting with a review of the previous lecture's content. The focus is on obtaining a more explicit formula for the function psi zero of tf, connecting it to the classical velocity and action. By deriving the relationship between the classical action and the function psi zero, the instructor demonstrates how the semiclassical propagator can be expressed in terms of the second derivative of the action. This leads to the Van Vleck - Pauli - Morette formula, a key result in quantum physics. The lecture concludes by hinting at a shift to a new topic, the fixed energy propagator.