The real-time dynamics of the asymmetric two-state system weakly interacting with a thermal environment is derived in a rather simple yet novel manner in the Heisenberg picture. Through second order in the coupling coefficients general formulae are obtained (i) for the quantum coherence...

In this paper we embark once more on the current discussion concerning the appropriate expression for the Lagrangian occurring in the action in the functional integral representation of continuous Markov processes. The equivalent differential equation representation of diffusion processes, that...

Using a nonlinear projection operator technique, the Markovian stochastic dynamics of a classical Brownian particle is derived in the case that the effective temperature is not constant. After recapitulating the general formalism and its application to isothermal Brownian motion, an isolated...

The classical noise activated equilibration process for a particle moving in a metastable potential well is considered as an eigenproblem. The smallest nonzero real eigenvalue of Kramers' Fokker-Planck model is evaluated analytically by means of Rayleigh's quotient. The treatment allows both for...

The exact dynamical solution is given for a harmonically bound particle of finite size (the oscillator) coupled rigidly to a finitely extended two-dimensional mechanical continuum transmission line (the membrane). A quantum mechanical ultraviolet divergence in the particle's momentum...