Physics and Mathematics Seminar: Are there trajectories in phase space of quantum systems?

When: March 28, 2017 – 2:00pm – 3:00pm

Ole Steuernagel (University of Hertfordshire and Brock University) will be giving a seminar entitled Are there trajectories in phase space of quantum systems? The talk will take place at 2:00 pm on Tuesday, March 28, 2017 in Mackenzie-Chown H-block room 313.


Phase-space dynamics in classical mechanics is described by transport along trajectories. It is thought by some that Heisenberg’s uncertainty principle does not allow for trajectories in phase space: that is incorrect. Here, I will explain what a phase space trajectory is.  Then I show that e.g. harmonic oscillator dynamics can be described with trajectories.But anharmonic quantum mechanical systems do not allow for a trajectory-based description of their phase-space dynamics. This invalidates some approaches to quantum phase-space studies.

An abstract plausibility argument against phase space trajectories in general is given. Then an explicit proof for all quantum phase-space distributions with negative values follows. This proof shows that the generation of coherences in anharmonic quantum mechanical systems is responsible for the occurrence of singularities in their phase-space velocity fields, explaining the numerical problems repeatedly reported in the literature. Our investigation provides deeper insight into the nature of quantum phase-space dynamics.

Location of your event: MCH 313
Cost: $0.00


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