Search results for "Computational methods in statistical physics and nonlinear dynamic"

showing 4 items of 4 documents

Transient Dynamics of Short Josephson Junctions under the influence of non-Gaussian Noise

2009

We investigate the effects of non-Gaussian white noise source on the transient dynamics of short Josephson junctions. The noise signal is simulated generating standard stable random variables with characteristic function described by Lévy index alpha and asymmetry parameter beta. We study the lifetime of the superconductive state as a function both of the frequency of the external driving bias current and the noise intensity for different values of index alpha. We compare our results with those obtained in the presence of Gaussian white noise. We find the presence of noise induced effects such as resonant activation and noise enhanced stability.

Josephson devicesStochastic processeComputational methods in statistical physics and nonlinear dynamicNoiseSettore FIS/03 - Fisica Della Materia
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THE ROLE OF NON-GAUSSIAN SOURCES IN THE TRANSIENT DYNAMICS OF LONG JOSEPHSON JUNCTIONS

2013

We analyze the effects of different non-Gaussian noise sources on the transient dynamics of an overdamped long Josephson junction. We find nonmonotonic behavior of the mean escape time as a function of the noise intensity and frequency of the external driving signal for all the noise sources investigated.

Josephson effectPhysicsFluctuation phenomena random processes noise and Brownian motionCondensed matter physicsGaussianJosephson devicesDynamics (mechanics)General Physics and AstronomyJosephson energyComputational methods in statistical physics and nonlinear dynamicSettore FIS/03 - Fisica Della MateriaPi Josephson junctionsymbols.namesakeRandom walks and Levy flightsymbolsTransient (oscillation)
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Co-occurrence of resonant activation and noise-enhanced stability in a model of cancer growth in the presence of immune response.

2006

We investigate a stochastic version of a simple enzymatic reaction which follows the generic Michaelis-Menten kinetics. At sufficiently high concentrations of reacting species, the molecular fluctuations can be approximated as a realization of a Brownian dynamics for which the model reaction kinetics takes on the form of a stochastic differential equation. After eliminating a fast kinetics, the model can be rephrased into a form of a one-dimensional overdamped Langevin equation. We discuss physical aspects of environmental noises acting in such a reduced system, pointing out the possibility of coexistence of dynamical regimes where noise-enhanced stability and resonant activation phenomena …

KineticsNoise intensityComputational methods in statistical physics and nonlinear dynamicNoise (electronics)Stability (probability)Quantitative Biology::Cell BehaviorImmune systemNeoplasmsChemical kinetics and dynamics.AnimalsHumansImmunologic FactorsComputer SimulationStatistical physicsQuantitative Biology - Populations and EvolutionCell ProliferationFluctuation phenomena random processes noise and Brownian motionStochastic ProcessesModels StatisticalStochastic processChemistryChemical kinetics in biological systemPopulations and Evolution (q-bio.PE)Models ImmunologicalImmunity InnateLangevin equationFOS: Biological sciencesNeoplastic cellBiological systemSignal TransductionPhysical review. E, Statistical, nonlinear, and soft matter physics
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Lifetime of the superconductive state in short and long Josephson junctions

2008

We study the transient statistical properties of short and long Josephson junctions under the influence of thermal and correlated fluctuations. In particular, we investigate the lifetime of the superconductive metastable state finding the presence of noise induced phenomena. For short Josephson junctions we investigate the lifetime as a function both of the frequency of the current driving signal and the noise intensity and we find how these noise-induced effects are modified by the presence of a correlated noise source. For long Josephson junctions we integrate numerically the sine-Gordon equation calculating the lifetime as a function of the length of the junction both for inhomogeneous a…

SuperconductivityPhysicsJosephson effectCondensed matter physicsCondensed Matter - SuperconductivityFOS: Physical sciencesBiasingCondensed Matter PhysicsSignalNoise (electronics)Settore FIS/03 - Fisica Della MateriaElectronic Optical and Magnetic MaterialsSuperconductivity (cond-mat.supr-con)MetastabilityCondensed Matter::SuperconductivityComputational methods in statistical physics and nonlinear dynamics Noise Fluctuations Josephson devices.Transient (oscillation)Maxima
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