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Upcoming:

Far-from-equilibrium dynamics of molecules in 4He nanodroplets: a quasiparticle perspective (NOTE UNUSUAL DAY AND TIME!)

Giacomo Bighin

Thu, 23 May 2019, 09:00

Giacomo Bighin

Thu, 23 May 2019, 09:00

Into the darkness: charting the Zona Galactica Incognita with Cepheids

Istvan Dekany

Thu, 23 May 2019, 11:15

Istvan Dekany

Thu, 23 May 2019, 11:15

Fundamental limitations for measurements in quantum many-body systems

Thomas Barthel

Thu, 23 May 2019, 14:15

Thomas Barthel

Thu, 23 May 2019, 14:15

For perturbative scalar field theories, the late-time-limit of the out-of-time-ordered correlation function that measures (quantum) chaos is shown to be equal to a Boltzmann-type kinetic equation that measures the total gross (instead of net) particle exchange between phase space cells, weighted by a function of energy. This derivation gives a concrete form to numerous attempts to derive chaotic many-body dynamics from ad hoc kinetic equations. As in conventional Boltzmann transport, which follows from the dynamics of the net particle number density exchange, the kernel of this kinetic integral equation is also set by the 2-to-2 scattering rate. This provides a mathematically precise statement of the known fact that in dilute weakly coupled gases late-time transport and early-time scrambling (or ergodicity) are controlled by the same physics.

Surprisingly infinitely strongly coupled, large-Nc theories with a holographic dual also possess this relation between early- and late-time physics. The gravitational shock wave computation used to extract the scrambling rate in strongly coupled quantum theories with a holographic dual is directly related to probing the system's hydrodynamic sound modes. At a special point along the sound dispersion relation curve, the residue of the retarded longitudinal stress-energy tensor two-point function vanishes. This pole-skipping point encodes the Lyapunov exponent of quantum chaos.

16 May 2019, 14:15

Institut für Theoretische Physik, Philosophenweg 19, Seminarraum