Van Winter Memorial Lecture: Quantum Revivals and the Modular Group

04/07/2016 - 4:00pm to 5:00pm
Speaker(s) / Presenter(s): 
Dr. John Cardy (University of Oxford and University of California, Berkeley)

If we start with a quantum system in a particular state and let it evolve undisturbed according to the rules of quantum mechanics, usually it will not return to its initial state. However, there are exceptions, for example a simple harmonic oscillator. More generally the existence of such quantum revivals is associated with an infinite-dimensional algebra which generates the spectrum of the hamiltonian. Important examples are rational conformal field theories in two and higher dimensions. I discuss these in detail and show how an action of the modular group implies a complicated time-dependence for the return amplitude, including incomplete revivals at all rational multiples of the fundamental frequency.

For more information on this and previous van Winter Memorial Lectures, please visit


Refreshments will be served in CP 179 at 3:45 PM

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