Jan Iwaniszewski - Academia.edu (original) (raw)

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Papers by Jan Iwaniszewski

Physics Letters, May 1, 1983

Abstract Starting from a Langevin equation with stationary gaussian noise of arbitrary correlatio... more Abstract Starting from a Langevin equation with stationary gaussian noise of arbitrary correlation time, a corresponding Fokker-Planck equation is derived under the condition of small noise strength.

Physical review, Aug 25, 2003

Nucleation and Atmospheric Aerosols, 2000

The problem of an escape over a fluctuating potential barrier is considered. The results of the a... more The problem of an escape over a fluctuating potential barrier is considered. The results of the analogue electronic experiment confirm the predictions about the dependence of the occurrence of the phenomena of resonant activation and inhibition of activation on the relation between the barrier noise parameters. We propose a new interpretation of the noise-induced resonance in this problem. A simple theoretical description valid for any correlation time is given.

Physical review, May 1, 2000

Physical review, Nov 1, 1994

EPL, May 27, 2008

... REFERENCES [1] Kramers HA, Physica, 7 (1940) 284. [2] Tobi D. and Bahar I., Proc. Natl. Acad.... more ... REFERENCES [1] Kramers HA, Physica, 7 (1940) 284. [2] Tobi D. and Bahar I., Proc. Natl. Acad. Sci. USA, 102 (2005) 18908. ... Rev. E, 74 (2006) 041904. [5] Doering CR and Gadoua JC, Phys. Rev. Lett., 69 (1992) 2318. [6] Madureira AJR, Hänggi P. and Wio HS, Phys. Lett. ...

Physical Review E, Jul 23, 2009

Il Nuovo Cimento D, Jul 1, 1995

SummaryThe phenomenon of stochastic resonance is predicted in a monostable system displaying tran... more SummaryThe phenomenon of stochastic resonance is predicted in a monostable system displaying transient bimodality during the evolution. The signal-to-noise ratio as a function of the noise intensity calculated within the rate equation theory with many simplifying assumptions exhibits a promising peak. The numerical simulations are also reported.

Journal of physics, Apr 21, 1995

The behaviour of a quantum kicked top subject to a dissipation mechanism is considered. Following... more The behaviour of a quantum kicked top subject to a dissipation mechanism is considered. Following Gisin and Percival (1992 J. Phys. A: Math. Gen. 25 5677) the dissipation is described by means of a diffusion process acting on the vector state; thus the dynamics is given by the stochastic Schrodinger equation. This approach allows one to treat numerically much larger quantum systems than with the use of a density operator. The calculations presented demonstrate an essential similarity between the classical and quantum counterparts of the top, the better the similarity the greater the quantum size of the problem. This concerns both the regular and chaotic behaviour of the top.

Physical review, Oct 1, 1996

Journal of physics, Apr 21, 1989

To describe a decay on an unstable state, a new systematic procedure is proposed for solving the ... more To describe a decay on an unstable state, a new systematic procedure is proposed for solving the Fokker-Planck equation with a small noise strength. The approximation assumes the correct small-time evolution and the Gaussian fluctuations around the most probable path for larger times. The exact stationary distribution is reached. The method may be easily adapted for calculating the multi-time correlation functions.

Physical Review A, Jun 1, 1992

A possibility of the occurrence of transient multimodality during a decay of an unstable state is... more A possibility of the occurrence of transient multimodality during a decay of an unstable state is analyzed. For the two discussed classes of systems it is found that the appearance of this phenomenon depends only on the sign of the second nonvanishing derivative of the potential at the unstable point. Thus here the transient multimodality is not a noise-induced phenomenon like that for the evolution from an arbitrary state. A scheme of the classification of dynamical systems based on their transient properties is proposed.

Open Systems & Information Dynamics, 2000

We investigate the problem of dissipative tunneling across a randomly modulated barrier in the tw... more We investigate the problem of dissipative tunneling across a randomly modulated barrier in the two-level approximation and within the quantum state diffusion approach. Introducing the Bloch sphere of all possible pure states of the system we analyse numerically the behaviour of stochastic quantum trajectories. If the barrier is static the coherent tunneling is suppressed by two types of diffusion; the state dependent one along the meridians of the sphere and the uniform one along its latitudes. The barrier fluctuations forced by dichotomic noise increases the first kind of diffusion. The strongest suppression of coherency occurs when the jump rate of the noise equals the amplitude of fluctuations. For large enough amplitudes we observe the decrease of the variance of two components of the Bloch vector, after the complete decay of their mean values.

AIP Conference Proceedings, 2000