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We study the Euler scheme for scalar non-autonomous stochastic differential equations, whose diffusion coefficient is not globally Lipschitz but a fractional power of a globally Lipschitz function. We analyse the strong error and establish…

Numerical Analysis · Mathematics 2024-01-17 Annalena Mickel , Andreas Neuenkirch

The linear response description for impurity diffusion in a granular fluid undergoing homogeneous cooling is developed in the preceeding paper. The formally exact Einstein and Green-Kubo expressions for the self-diffusion coefficient are…

Soft Condensed Matter · Physics 2009-11-07 James Lutsko , J. Javier Brey , James W. Dufty

We consider the spreading dynamics of the Fisher-KPP equation in a shifting environment, by analyzing the limit of the rate function of the solutions. For environments with a weak monotone condition, it was demonstrated in a previous paper…

Analysis of PDEs · Mathematics 2024-10-21 King-Yeung Lam , Gregoire Nadin , Xiao Yu

We derive and apply a partial differential equation for the moment generating function of the Wright-Fisher model of population genetics.

Probability · Mathematics 2020-03-11 Tat Dat Tran , Julian Hofrichter , Juergen Jost

In this paper we study $g$-fractional diffusion on bounded domains in $\mathbb{R}^d$ with absorbing boundary conditions. We show the explicit representation of the solution and then we study the first passage time distribution, showing the…

Analysis of PDEs · Mathematics 2023-03-09 L. Angelani , R. Garra

We are interested in the time asymptotic location of the level sets of solutions to Fisher-KPP reaction-diffusion equations with fractional diffusion in periodic media. We show that the speed of propagation is exponential in time, with a…

Analysis of PDEs · Mathematics 2012-09-24 Xavier Cabre , Anne-Charline Coulon , Jean-Michel Roquejoffre

Models of diffusion in white dwarfs universally rely on the coefficients calculated by Paquette et al. (1986). We present new calculations of diffusion coefficients based on an advanced microscopic theory of dense plasmas and a numerical…

Solar and Stellar Astrophysics · Physics 2014-10-29 D. Saumon , C. E. Starrett , J. Daligault

Using the transport-of-intensity approach for free-space optical propagation in the paraxial regime, we show that diffraction is fundamentally related to the Fisher information associated with models of the transverse intensity…

Optics · Physics 2026-01-16 Jonathan M. Nichols , Frank Bucholtz

We derive an Ito-formula for the Dawson-Watanabe superprocess, a well-known class of measure-valued processes, extending the classical Ito-formula with respect to two aspects. Firstly, we extend the state-space of the underlying process…

Probability · Mathematics 2020-10-07 Christian Mandler , Ludger Overbeck

We study the seismic inverse problem for the recovery of subsurface properties in acoustic media. In order to reduce the ill-posedness of the problem, the heterogeneous wave speed parameter to be recovered is represented using a limited…

Analysis of PDEs · Mathematics 2020-09-10 Florian Faucher , Otmar Scherzer , Hélène Barucq

The convolution quadrature method originally developed for the Riemann-Liouville fractional calculus is extended in this work to the Hadamard fractional calculus by using the exponential type meshes. Local truncation error analysis is…

Numerical Analysis · Mathematics 2023-11-14 Baoli Yin , Guoyu Zhang , Yang Liu , Hong Li

We study approximations of reflected It\^o diffusions on convex subsets $D$ of $\Rd$ by solutions of stochastic differential equations with penalization terms. We assume that the diffusion coefficients are merely measurable (possibly…

Probability · Mathematics 2012-07-02 Leszek Slominski

The dispersion of a diffusive scalar in a fluid flowing through a network has many applications including to biological flows, porous media, water supply and urban pollution. Motivated by this, we develop a large-deviation theory that…

Fluid Dynamics · Physics 2016-09-14 Alexandra Tzella , Jacques Vanneste

We reconsider the problem of diffusion of particles at constant speed and present a generalization of the Telegrapher process to higher dimensional stochastic media ($d>1$), where the particle can move along $2^d$ directions. We derive the…

Disordered Systems and Neural Networks · Physics 2009-10-31 S. Anantha Ramakrishna , N. Kumar

Yet another proof of Onsager-Machlup formula for diffusion processes on a Riemannian manifold after Takahashi-Watanabe, Fujita-Kotani. The proof is purely probabilistic and contains a precise study on an ergodic effect for a key Wiener…

Probability · Mathematics 2016-10-24 Keisuke Hara , Yoichiro Takahashi

Yeh and Hummer's simplified estimation method has often been adopted to obtain diffusion coefficients for solute molecules using molecular dynamic simulation. However, the simplified formula is not necessarily valid when a small basic cell…

Chemical Physics · Physics 2022-10-19 Tomoya Iwashita , Masaaki Nagao , Akira Yoshimori , Masahide Terazima , Ryo Akiyama

The Wigner Transform (WT) has been extensively used in the formulation of phase-space models for a variety of wave propagation problems including high-frequency limits, nonlinear and random waves. It is well known that the WT features…

Analysis of PDEs · Mathematics 2015-05-19 Agissilaos G. Athanassoulis

The generalised eigenfunction expansion method (GEM) and the singularity expansion method (SEM) are applied to solve the canonical problem of wave scattering on an infinite stretched string in the time domain. The GEM, which is shown to be…

Mathematical Physics · Physics 2025-03-28 Ben Wilks , Michael H. Meylan , Fabien Montiel , Sarah Wakes

In this paper we study the {\it pathwise stochastic Taylor expansion}, in the sense of our previous work \cite{Buckdahn_Ma_02}, for a class of It\^o-type random fields in which the diffusion part is allowed to contain both the random field…

Probability · Mathematics 2010-08-20 Rainer Buckdahn , Ingo Bulla , Jin Ma

This paper discusses certain properties of heterogeneous hypergeometric functions with two matrix arguments. These functions are newly defined but have already appeared in statistical literature and are useful when dealing with the…

Statistics Theory · Mathematics 2020-12-09 Koki Shimizu , Hiroki Hashiguchi