RESUMEN
The response of a trapping overdamped monostable system to a harmonic perturbation is analyzed, in the context of stochastic resonance phenomenon. We consider the dynamics of a Brownian particle moving in a piecewise linear potential with a white Gaussian noise source. Based on linear-response theory and Laplace transform technique, analytical expressions of signal-to-noise ratio (SNR) and signal power amplification (SPA) are obtained. We find that the SNR is a nonmonotonic function of the noise intensity, while the SPA is monotonic. Theoretical results are compared with numerical simulations.
RESUMEN
We study the effect of noise-enhanced stability of periodically driven metastable states in a system described by piecewise linear potential. We find that the growing of the average escape time with the intensity of the noise is depending on the initial condition of the system. We analytically obtain the condition for the noise enhanced stability effect and verify it by numerical simulations.
RESUMEN
We study the causes of noise delayed decay of unstable states in nonlinear dynamic systems within the framework of the overdamped Brownian motion model. For the analysis, we use the exact expressions for the decay times of unstable states, which take into account the inverse probability current in contrast to the well-known mean first passage time method. These expressions are valid for any intensity of fluctuations and for arbitrary potential profiles. The effect of delay is shown to arise under the decay of unstable nonequilibrium states due to the action of two different mechanisms. These mechanisms are caused by the inverse probability current and by the nonlinearity of potential describing an unstable state.
RESUMEN
The isotherm of a Van der Waals substance, containing only stable points, is obtained on the basis of using the thermodynamic potential for nonequilibrium states and taking fluctuations into account. It is shown that in the vicinity of two-phase states this isotherm is close to the horizontal phase equilibrium line, defined by Maxwell's rule. The lifetimes of the metastable states of the Van der Waals substance, which depend on the intensity of the external fluctuations and the number of particles in the system, are estimated. (c) 1994 American Institute of Physics.