Now showing items 5-24 of 60

• #### Darrieus-Landau instabilities in the framework of the G-equation ﻿

(2017-04)
We consider a model formulation of the flame front propagation in turbulent premixed combustion based on stochastic fluctuations imposed to the mean flame position. In particular, the mean flame motion is described by ...
• #### Discretizations of the spectral fractional Laplacian on general domains with Dirichlet, Neumann, and Robin boundary conditions ﻿

(2017-04-28)
In this work, we propose novel discretisations of the spectral fractional Laplacian on bounded domains based on the integral formulation of the operator via the heat-semigroup formalism. Specifically, we combine suitable ...
• #### Effective self-similar expansion for the Gross-Pitaevskii equation ﻿

(2018-04)
We consider an effective scaling approach for the free expansion of a one-dimensional quantum wave packet, consisting in a self-similar evolution to be satisfied on average, i.e., by integrating over the coordinates. A ...
• #### The emergence of self-organization in complex systems-Preface ﻿

(2015-12-31)
[No abstract available]
• #### Exact distributions of the maximum and range of random diffusivity processes ﻿

(2021-02-09)
We study the extremal properties of a stochastic process $x_t$ defined by the Langevin equation ${\dot {x}}_{t}=\sqrt{2{D}_{t}}\enspace {\xi }_{t}$, in which $\xi_t$ is a Gaussian white noise with zero mean and $D_t$ is a ...
• #### Exact first-passage time distributions for three random diffusivity models ﻿

(2021-01-04)
We study the extremal properties of a stochastic process $x_t$ defined by a Langevin equation $\dot{x}= \sqrt{2D_o V (B_t )} \xi_t$, where $\xi$ is a Gaussian white noise with zero mean, $D_0$ is a constant scale factor, ...
• #### Finite-energy Lévy-type motion through heterogeneous ensemble of Brownian particles ﻿

(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 ...
• #### Fire-spotting generated fires. Part I: The role of atmospheric stability ﻿

(2019-02)
This is the first part of two papers concerning fire-spotting generated fires. In this part we deal with the impact of macroscale factors, such as the atmospheric stability, and in the second part we deal with mesoscale ...
• #### Fractional Brownian motion in a finite interval: correlations effect depletion or accretion zones of particles near boundaries ﻿

(2019-02)
Fractional Brownian motion (FBM) is a Gaussian stochastic process with stationary, long-time correlated increments and is frequently used to model anomalous diffusion processes. We study numerically FBM confined to a finite ...
• #### Fractional kinetics emerging from ergodicity breaking in random media ﻿

(2016)
We present a modelling approach for diffusion in a complex medium characterized by a random lengthscale. The resulting stochastic process shows subdiffusion with a behavior in qualitative agreement with single particle ...
• #### Fractional kinetics in random/complex media ﻿

(2019)
In this chapter, we consider a randomly-scaled Gaussian process and discuss a number of applications to model fractional diffusion. Actually, this approach can be understood as a Gaussian diffusion in a medium characterized ...
• #### Fractional relaxation with time-varying coefficient ﻿

(2014-12-31)
From the point of view of the general theory of the hyper-Bessel operators, we consider a particular operator that is suitable to generalize the standard process of relaxation by taking into account both memory effects of ...
• #### From G - Equation to Michelson - Sivashinsky Equation in Turbulent Premixed Combustion Modelling ﻿

(2017-06-20)
It is well known that the Michelson-Sivashinky equation describes hydrodynamic instabilities in turbulent premixed combustion. Here a formulation of the flame front propagation based on the G-equation and on stochastic ...
• #### Front Curvature Evolution and Hydrodynamics Instabilities ﻿

(2017-06-07)
It is known that hydrodynamic instabilities in turbulent premixed combustion are described by the Michelson-Sivashinsky (MS) equation. A model of the flame front propagation based on the G-equation and on stochastic ...
• #### Front propagation in anomalous diffusive media governed by time-fractional diffusion ﻿

(2014-12-31)
In this paper, a multi-dimensional model is proposed to study the propagation of random fronts in media in which anomalous diffusion takes place. The front position is obtained as the weighted mean of fronts calculated by ...
• #### Front Propagation in Random Media ﻿

(2019)
This PhD thesis deals with the problem of the propagation of fronts under random circumstances. A statistical model to represent the motion of fronts when are evolving in a media characterized by microscopical randomness ...
• #### Gaussian processes in complex media: new vistas on anomalous diffusion ﻿

(2019-09)
Normal or Brownian diffusion is historically identified by the linear growth in time of the variance and by a Gaussian shape of the displacement distribution. Processes departing from the at least one of the above conditions ...
• #### A generalized Stefan model accounting for system memory and non-locality ﻿

(2020-05)
The Stefan problem, involving the tracking of an evolving phase-change front, is the prototypical example of a moving boundary problem. In basic one- dimensional problems it is well known that the front advances as the ...
• #### Gut microbiota ecology: Biodiversity estimated from hybrid neutral-niche model increases with health status and aging ﻿

(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 ...
• #### A hypothesis about parallelism vs. seriality in dreams ﻿

(2019-10-10)
The current article discusses the hypothesis about parallelism vs. Seriality in dreams. The process of dream building implies the construction of a complex network of closely interrelated sources. On the other hand, the ...