Search results for "Noise intensity"

showing 5 items of 5 documents

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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Noise Enhanced Stability in Fluctuating Metastable States

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 o…

Nonlinear systemStatistical Mechanics (cond-mat.stat-mech)MetastabilityQuantum mechanicsSoft Condensed Matter (cond-mat.soft)FOS: Physical sciencesNoise intensityStatistical physicsWhite noiseCondensed Matter - Soft Condensed MatterBrownian motionCondensed Matter - Statistical MechanicsMathematics
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Time characteristics of Lévy flights in a steep potential well

2013

Using the method previously developed for ordinary Brownian diffusion, we derive a new formula to calculate the correlation time of stationary Lévy flights in a steep potential well. For the symmetric quartic potential, we obtain the exact expression of the correlation time of steady-state Lévy flights with index α = 1. The correlation time of stationary Lévy flights decreases with an increasing noise intensity and steepness of potential well.

PhysicsMathematics::ProbabilityLévy flightQuartic functionGeneral Physics and AstronomyNoise intensityGeneral Materials ScienceLévy flights Kolmogorov equation Frcational Fokker-Planck equation Stochastic Dynamics (theory) Methods of Stochastic Analysis Exact resultsStatistical physicsPhysical and Theoretical ChemistrySettore FIS/03 - Fisica Della MateriaBrownian motionThe European Physical Journal Special Topics
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Noise Enhanced Stability in an Unstable System

1996

We experimentally detect noise enhanced stability in an unstable physical system. The average escape time from a metastable, periodically driven, system is measured in the stable and unstable regimes in a noisy environment. In the unstable regime, we measure that the average escape time has a maximum for a finite value of the noise intensity. The scaling properties of the average escape time and of the variance of escape times are compared with the predictions obtained for a system in a marginal state.

PhysicsMetastabilityPhysical systemGeneral Physics and AstronomyNoise intensityMechanicsMeasure (mathematics)Stability (probability)ScalingNoise (radio)Physical Review Letters
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Noise delayed decay of unstable states: theory versus numerical simulations

2004

We study the noise delayed decay of unstable nonequilibrium states in nonlinear dynamical systems within the framework of the overdamped Brownian motion model. We give the exact expressions for the decay times of unstable states for polynomial potential profiles and obtain nonmonotonic behavior of the decay times as a function of the noise intensity for the unstable nonequilibrium states. The analytical results are compared with numerical simulations.

PhysicsPolynomialStatistical Mechanics (cond-mat.stat-mech)FOS: Physical sciencesGeneral Physics and AstronomyNoise intensityNon-equilibrium thermodynamicsStatistical and Nonlinear PhysicsFunction (mathematics)Nonlinear dynamical systemsnumerical simulationsBrownian motion modelStatistical physicsCondensed Matter - Statistical MechanicsMathematical PhysicsNoise (radio)
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