Browsing Statistical Physics by Author "Vitali, S."
Now showing items 1-9 of 9
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Centre-of-mass like superposition of Ornstein-Uhlenbeck processes: A pathway to non-autonomous stochastic differential equations and to fractional diffusion
D’Ovidio, M.; Vitali, S.
; Sposini, V.; Sliusarenko, O.; Paradisi, P.; Castellani, G.; Pagnini, G. (2018-10-25)
We consider an ensemble of Ornstein–Uhlenbeck processes featuring a population of relaxation times and a population of noise amplitudes that characterize the heterogeneity of the ensemble. We show that the centre-of-mass ... -
Finite-energy Lévy-type motion through heterogeneous ensemble of Brownian particles
Sliusarenko, O.; Vitali, S.; Sposini, V.; Paradisi, P.; Chechkin, A.V.; Castellani, G.; Pagnini, G. (2019-02-01)
Complex systems are known to display anomalous diffusion, whose signature is a space/time scaling $x \sim t^\delta$ with $\delta \neq 1/2$ in the probability density function (PDF). Anomalous diffusion can emerge jointly ... -
Fractional Diffusion and Medium Heterogeneity: The Case of the Continuos Time Random Walk
Sposini, V.; Vitali, S.; Paradisi, P.; Pagnini, G. (2021-07-24)
In this contribution we show that fractional diffusion emerges from a simple Markovian Gaussian random walk when the medium displays a power-law heterogeneity. Within the framework of the continuous time random walk, the ... -
Gut microbiota ecology: Biodiversity estimated from hybrid neutral-niche model increases with health status and aging
Sala, C.; Giampieri, E.; Vitali, S.; Garagnani, P.; Remondini, D.; Bazzani, A.; Franceschi, C.; Castellani, G. (2020-10-30)
In this work we propose an index to estimate the gut microbiota biodiversity using a modeling approach with the aim of describing its relationship with health and aging. The gut microbiota, a complex ecosystem that links ... -
Langevin equation in complex media and anomalous diffusion
Vitali, S.; Sposini, V.; Sliusarenko, O.; Paradisi, P.; Castellani, G.; Pagnini, G. (2018-07-30)
The problem of biological motion is a very intriguing and topical issue. Many efforts are being focused on the development of novel modelling approaches for the description of anomalous diffusion in biological systems, such ... -
Modeling of birth-death and diffusion processes in biological complex environments
Vitali, S. (2018-04-20)
This thesis is centered on the theory of stochastic processes and their applications in biological systems characterized by a complex environment. Three case studies have been modeled by the use of the three fundamental ... -
SHOULD I STAY OR SHOULD I GO? ZERO-SIZE JUMPS IN RANDOM WALKS FOR LÉVY FLIGHTS
Pagnini, G.; Vitali, S. (2021-02)
We study Markovian continuous-time random walk models for Lévy flights and we show an example in which the convergence to stable densities is not guaranteed when jumps follow a bi-modal power-law distribution that is equal ... -
Stochastic Properties of Colliding Hard Spheres in a Non-equilibrium Thermal Bath
Bazzani, A.; Vitali, S.; Montanari, C.; Monti, M.; Rambaldi, S.; Castellani, G. (2021-07-24)
We consider the problem of describing the dynamics of a test particle moving in a thermal bath using the stochastic differential equations. We briefly recall the stochastic approach to the Brownian based on the statistical ... -
Study of Wound Healing Dynamics by Single Pseudo-Particle Tracking in Phase Contrast Images Acquired in Time-Lapse
Scheda, R.; Vitali, S.; Giampieri, E.; Pagnini, G.; Zironi, I. (2021-03)
Cellular contacts modify the way cells migrate in a cohesive group with respect to a free single cell. The resulting motion is persistent and correlated, with cells’ velocities self-aligning in time. The presence of a dense ...