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We study nonlinear stability of spatially homogeneous oscillations in reaction-diffusion systems. Assuming absence of unstable linear modes and linear diffusive behavior for the neutral phase, we prove that spatially localized perturbations…

偏微分方程分析 · 数学 2008-07-01 Thierry Gallay , Arnd Scheel

In this paper, we introduce and analyze a numerical scheme for solving the Cauchy-Dirichlet problem associated with fractional nonlinear diffusion equations. These equations generalize the porous medium equation and the fast diffusion…

数值分析 · 数学 2024-09-30 Hélène Hivert , Florian Salin

We consider a time-dependent linear diffusion equation together with a related inverse boundary value problem. The aim of the inverse problem is to determine, based on observations on the boundary, the non-homogeneous diffusion coefficient…

数值分析 · 数学 2016-09-21 Lauri Mustonen

We address the inverse problem of identifying a time-dependent potential coefficient in a one-dimensional diffusion equation subject to Dirichlet boundary conditions and a nonlocal integral overdetermination constraint reflecting spatially…

数值分析 · 数学 2025-11-12 Arshyn Altybay , Michael Ruzhansky

We consider the initial/boundary value problem for the fractional diffusion and diffusion-wave equations involving a Caputo fractional derivative in time. We develop two "simple" fully discrete schemes based on the Galerkin finite element…

数值分析 · 数学 2015-10-13 Bangti Jin , Raytcho Lazarov , Zhi Zhou

We are interested in the kernel of one-dimensional diffusion equations with continuous coefficients as evaluated by means of explicit discretization schemes of uniform step $h>0$ in the limit as $h\to0$. We consider both semidiscrete…

数值分析 · 数学 2007-11-02 Claudio Albanese

In this paper, a space-time discontinuous Galerkin finite element method for distributed optimal control problems governed by unsteady diffusion-convection-reaction equations with control constraints is studied. Time discretization is…

最优化与控制 · 数学 2013-08-09 Tuğba Akman , Bülent Karasözen

In this paper, we study the large--time behavior of a numerical scheme discretizing drift-- diffusion systems for semiconductors. The numerical method is finite volume in space, implicit in time, and the numerical fluxes are a…

数值分析 · 数学 2019-04-22 Marianne Bessemoulin-Chatard , Claire Chainais-Hillairet

We develop a unified and easy to use framework to study robust fully discrete numerical methods for nonlinear degenerate diffusion equations $$ \partial_t u-\mathfrak{L}^{\sigma,\mu}[\varphi(u)]=f \quad\quad\text{in}\quad\quad…

数值分析 · 数学 2019-06-20 Félix del Teso , Jørgen Endal , Espen R. Jakobsen

The paper introduces a finite element method for an Eulerian formulation of partial differential equations governing the transport and diffusion of a scalar quantity in a time-dependent domain. The method follows the idea from Lehrenfeld &…

数值分析 · 数学 2025-06-26 Maxim Olshanskii , Henry von Wahl

Numerically solving high-dimensional random parametric PDEs poses a challenging computational problem. It is well-known that numerical methods can greatly benefit from adaptive refinement algorithms, in particular when functional…

数值分析 · 数学 2024-07-29 Martin Eigel , Nando Hegemann

In this article we present an a posteriori error estimator for the spatial-stochastic error of a Galerkin-type discretisation of an initial value problem for a random hyperbolic conservation law. For the stochastic discretisation we use the…

数值分析 · 数学 2019-02-22 Jan Giesselmann , Fabian Meyer , Christian Rohde

We study the inverse problem in Optical Tomography of determining the optical properties of a medium $\Omega\subset\mathbb{R}^n$, with $n\geq 3$, under the so-called diffusion approximation. We consider the time-harmonic case where $\Omega$…

偏微分方程分析 · 数学 2021-11-16 Jason Curran , Romina Gaburro , Clifford J. Nolan , Erkki Somersalo

This paper studies the original discrete-time denoising diffusion probabilistic model (DDPM) from a probabilistic point of view. We present three main theoretical results. First, we show that the time-dependent score function associated…

概率论 · 数学 2026-01-13 Yumiharu Nakano

In this article we study the numerical approximation of a variable coefficient fractional diffusion equation. Using a change of variable, the variable coefficient fractional diffusion equation is transformed into a constant coefficient…

数值分析 · 数学 2019-02-28 Xiangcheng Zheng , V. J. Ervin , Hong Wang

We formulate a stabilized quasi-optimal Petrov-Galerkin method for singularly perturbed convection-diffusion problems based on the variational multiscale method. The stabilization is of Petrov-Galerkin type with a standard finite element…

数值分析 · 数学 2016-06-16 Guanglian Li , Daniel Peterseim , Mira Schedensack

This paper is devoted to the error analysis of a time-spectral algorithm for fractional diffusion problems of order $\alpha$ ($0 < \alpha < 1$). The solution regularity in the Sobolev space is revisited, and new regularity results in the…

数值分析 · 数学 2021-06-08 Hao Luo , Xiaoping Xie

This paper is concerned with an inverse problem of recovering a potential term and fractional order in a one-dimensional subdiffusion problem, which involves a Djrbashian-Caputo fractional derivative of order $\alpha\in(0,1)$ in time, from…

偏微分方程分析 · 数学 2021-09-22 Bangti Jin , Zhi Zhou

In this paper, we investigate a nonlinear inverse problem aimed at recovering a coefficient $a(t, x)$, dependent on both time and a subset of spatial variables, in a diffusion equation \( u_t - \Delta_x u - u_{yy} +a(t, x) u = f(t,x,y) \),…

偏微分方程分析 · 数学 2025-08-07 R. R. Ashurov , O. T. Mukhiddinova

In this paper, a diffusion-aggregation equation with delta potential is introduced. Based on the global existence and uniform estimates of solutions to the diffusion-aggregation equation, we also provide the rigorous derivation from a…

偏微分方程分析 · 数学 2019-12-13 Li Chen , Simone Göttlich , Stephan Knapp