  In this work we make a high precision numerical study of the Ehrenfest
theorem using the Bohmian approach, where we obtain classical solutions from
the quantum trajectories performing the Bohmian averages. We analyse the
one-dimensional quantum harmonic and Duffing oscillator cases, finding
numerical solutions of the time-dependent Schr\"odinger equation and the
guidance equation for different sets of initial conditions and connects these
results with the corresponding classical solutions. We also investigate the
effect of introducing external forces of three types: a simple constant force,
a fast-acting Gaussian impulse, and an oscillatory force with different
frequencies. In the last case the resonance in the quantum trajectories was
observed.

Quantum Physics