Search results for " Langevin equation."

showing 5 items of 5 documents

Noise enhanced stability in fluctuating metastable states Phys. Rev. E69, 061103 (2004)

2004

We derive general equations for the nonlinear relaxation time of Brownian diffusion in randomly switching potential with a sink. For piece-wise linear dichotomously fluctuating potential with metastable state, we obtain the exact average lifetime as a function of the potential parameters and the noise intensity. Our result is valid for arbitrary white noise intensity and for arbitrary fluctuation rate of the potential. We find noise enhanced stability phenomenon in the system investigated: The average lifetime of the metastable state is greater than the time obtained in the absence of additive white noise.We obtain the parameter region of the fluctuating potential where the effect can be ob…

Fluctuation phenomena random processes noise and Brownian motionStochastic analysis methods Fokker-Planck equation Langevin equation.Probability theory stochastic processes and statistic
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Suppression of timing errors in short overdamped Josephson junctions

2004

The influence of fluctuations and periodical driving on temporal characteristics of short overdamped Josephson junction is analyzed. We obtain the standard deviation of the switching time in the presence of a dichotomous driving force for arbitrary noise intensity and in the frequency range of practical interest. For sinusoidal driving the resonant activation effect has been observed. The mean switching time and its standard deviation have a minimum as a function of driving frequency. As a consequence the optimization of the system for fast operation will simultaneously lead to minimization of timing errors.

PhysicsJosephson effectSuperconductivityFluctuation phenomena random processes noise and Brownian motionStatistical Mechanics (cond-mat.stat-mech)Numerical analysisCondensed Matter - SuperconductivityGeneral Physics and AstronomyFOS: Physical sciencesStatistical mechanicsFunction (mathematics)Standard deviationSwitching timeSuperconductivity (cond-mat.supr-con)Range (statistics)Statistical physicsStochastic analysis methods Fokker-Planck equation Langevin equationCondensed Matter - Statistical MechanicsSuperconducting device
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Predator population depending on lemming cycles

2016

In this paper, a Langevin equation for predator population with multiplicative correlated noise is analyzed. The noise source, which is a nonnegative random pulse noise with regulated periodicity, corresponds to the prey population cycling. The increase of periodicity of noise affects the average predator density at the stationary state.

Settore FIS/02 - Fisica Teorica Modelli E Metodi MatematiciPopulationDead-time-distorted Poisson proceDead-time-distorted Poisson process; Langevin equation; Noise in biological systems; population dynamics; Condensed Matter Physics; Statistical and Nonlinear PhysicsCondensed Matter PhysicNoise in biological system01 natural sciences010305 fluids & plasmasLangevin equation0103 physical sciencesQuantitative Biology::Populations and EvolutionStatistical physics010306 general physicseducationPredatorMathematicsPulse noiseeducation.field_of_studyStochastic processMultiplicative functionStatistical and Nonlinear PhysicsCondensed Matter Physicspopulation dynamicLangevin equationNoiseStationary state
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Translocation dynamics of a short polymer driven by an oscillating force

2013

Under the terms of the Creative Commons Attribution 3.0 Unported License.

chemistry.chemical_classificationQuantitative Biology::BiomoleculesField (physics)Polymersmedia_common.quotation_subjectDynamics (mechanics)General Physics and AstronomyMonotonic functionPolymerFunction (mathematics)InertiaSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Settore FIS/03 - Fisica Della MateriaQuantitative Biology::Subcellular ProcessesCondensed Matter::Soft Condensed MatterLangevin equationchemistryChemical physicsMetastabilityPolymer translocation Complex Systems Langevin equation Stochastic modelingThermodynamicsStatistical physicsPhysical and Theoretical Chemistrymedia_common
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Detector's quantum backaction effects on a mesoscopic conductor and fluctuation-dissipation relation

2017

International audience; When measuring quantum mechanical properties of charge transport in mesoscopic conductors, backaction effects occur. We consider a measurement setup with an elementary quantum circuit, composed of an inductance and a capacitor, as detector of the current flowing in a nearby quantum point contact. A quantum Langevin equation for the detector variable including backaction effects is derived. Differences with the quantum Langevin equation obtained in linear response are pointed out. In this last case, a relation between fluctuations and dissipation is obtained, provided that an effective temperature of the quantum point contact is defined.

fluctuation-dissipation relationfluctuation-dissipation relation; mesoscopic conductor; Quantum backaction; quantum Langevin equation; Physics and Astronomy (all)Physics and Astronomy (all)quantum Langevin equationQuantum backaction mesoscopic conductor quantum Langevin equation fluctuation-dissipation relation.Quantum backactionmesoscopic conductorSettore FIS/03 - Fisica Della Materia[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
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