---

AVVISO di SEMINARIO Dr. Gianni Pagnini BCAM & Ikerbasque, Bilbao, Spain

Title: Fractional diffusion as an intermediate asymptotic regime.

Abstract: A continuous-time random walk driven by two different Markovian hopping-trap mechanisms is investigated and it is shown that the paradigmatic features of anomalous diffusion are met. More precisely, anomalous diffusion results from a process that goes through the action of two co-existing Markovian mechanisms acting with different statistical frequency, and the probability of occurrence of this switch between the two Markovian settings originates and fully characterises the anomalous diffusion. In fact, ensemble and single-particle observables of this model have been studied and they match the main characteristics of anomalous diffusion as they are typically measured in living systems. In particular, the celebrated transition of the walker?s distribution from exponential to stretched-exponential and finally to Gaussian distribution is displayed by including also the Brownian yet non-Gaussian interval. Moreover, the model dynamically provides the power-law exponent of the mean-square displacement as a function of the probability of switching between the two Markovian states, namely the fractional order. Hence, fractional diffusion emerges as an intermediate asymptotic regime. Finally, within the present approach, fractional diffusion can be interpreted as a mathematical method for bridging two co-existing equilibrium states in a disordered medium. This talk is based on: Vitali S, Paradisi P and Pagnini 2022 J. Phys. A: Math. Theor. 55 224012

Il seminario si terrà il giorno 3 Novembre 2022 ore 16:00 nella Aula D primo livello del Dipartimento Matematica e Applicazioni, Università di Napoli FEDERICO II, Complesso di Monte Sant'Angelo, Via Cintia, Napoli.

-- Link per seguire online:

https://teams.microsoft.com/l/meetup-join/19%3aMQ4RZDBo_0G-K_PHxKtktVYAczOGb...