257 citations · 1.1k across the 71 of their papers we have counts for
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Action for classical, quantum, closed and open systems
Janos Polonyi
It is well known that the action functional can be used to define classical, quantum, closed, and open dynamics in a generalization of the variational principle and in the path int…
Macroscopic limit of quantum systems
Janos Polonyi
Classical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, deri…
Elementary open quantum states
Janos Polonyi, Ines Rachid
It is shown that the mixed states of a closed dynamics support a reduplicated symmetry, which is reduced back to the subgroup of the original symmetry group when the dynamics is op…
Equilibrium properties and decoherence of an open harmonic oscillator
Janos Polonyi
The equilibrium properties of an open harmonic oscillator are considered in three steps: First the creation and destruction operators are generalized for open dynamics and the crea…
Electric current in a translation invariant environment
Janos Polonyi, Ines Rachid
The master equation for the reduced density matrix of a charged particle interacting with a translation invariant weakly coupled environment is considered. The electric current is…
Instantaneous and dynamical decoherence
Janos Polonyi
Two manifestations of decoherence, called instantaneous and dynamical, are investigated. The former reflects the suppression of the interference between the components of the curre…
Time scale of stationary decoherence
Janos Polonyi
The decoherence of a test particle interacting with an ideal gas is studied by the help of the effective Lagrangian, derived in the leading order of the perturbation expansion and…
Environment Induced Time Arrow and the Closed Time Path method
Janos Polonyi
It is shown in the framework of a harmonic system that the thermodynamical time arrow is induced by the environmental initial conditions in a manner similar to spontaneous symmetry…
Semiclassical Coulomb field
Janos Polonyi
The contribution of different modes of the Coulomb field to decoherence and to the dynamical breakdown of the time reversal invariance is calculated in the one-loop approximation f…