Berlin 2012 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 4: Quantum Dynamics, Decoherence, and Quantum Information

DY 4.1: Talk

Monday, March 26, 2012, 15:00–15:15, MA 001

Langevin trajectories deriving from quantum histories — •Hendrik Niemeyer and Jochen Gemmer — Universität Osnabrück, Barbarastraße 7, D-49069 Osnabrück

Our point of departure is the Pauli master equation and its conceptual framework. According to the latter a "property" of a system such as a particle being in a certain region in space or two macroscopic objects featuring a certain temperature difference, etc. corresponds to a (projective) subspace of full Hilbert space. The Pauli master equation suggests transitions between these quantitiative properties (which we choose to call ``mesostates'') with rates given by Fermis Golden Rule. We show that assuming such rates as well as Gaussian scaling of the dimension of the above subspace with the mesostate and an exponential relaxation of the average mesostate neccessarily yields Langevin-type stochastic dynamics for the mesostate. From a purely quantum perspective the Langevin trajectories then correspond to quantum consistent and markovian histories.