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Complete positivity of nonlinear evolution: A case study

Marek Czachor·Maciej Kuna
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Abstract

Simple Hartree-type equations lead to dynamics of a subsystem that is not completely positive in the sense accepted in mathematical literature. In the linear case this would imply that negative probabilities have to appear for some system that contains the subsystem in question. In the nonlinear case this does not happen because the mathematical definition is physically unfitting as shown on a concrete example.

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Marek Czachor, Maciej Kuna. 1998-04-07. Complete positivity of nonlinear evolution: A case study. https://doi.org/10.1103/physreva.58.128

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