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Related papers: Lagrangian for the Convection-Diffusion Equation

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In this paper we investigate the solution of generalized distributed order diffusion equations with composite time fractional derivative by using the Fourier-Laplace transform method. We represent solutions in terms of infinite series in…

Mathematical Physics · Physics 2017-03-17 Trifce Sandev , Zivorad Tomovski , Bojan Crnkovic

Explicit solutions of differential equations of complex fractional orders with respect to functions and with continuous variable coefficients are established. The representations of solutions are given in terms of some convergent infinite…

Classical Analysis and ODEs · Mathematics 2021-03-15 Joel E. Restrepo , Michael Ruzhansky , Durvudkhan Suragan

We present a fluid dynamics video which illustrates the Lagrangian aspects of local heat transfer in turbulent Rayleigh-Benard convection. The data are obtained from a direct numerical simulation.

Fluid Dynamics · Physics 2015-05-14 Maik Boltes , Herwig Zilken , Joerg Schumacher

We consider an evolution equation whose time-diffusion is of fractional type and we provide decay estimates in time for the $L^s$-norm of the solutions in a bounded domain. The spatial operator that we take into account is very general and…

Analysis of PDEs · Mathematics 2018-08-24 Serena Dipierro , Enrico Valdinoci , Vincenzo Vespri

In this note we consider generalized diffusion equations in which the diffusivity coefficient is not necessarily constant in time, but instead it solves a nonlinear fractional differential equation involving fractional Riemann-Liouville…

Probability · Mathematics 2022-09-21 Roberto Garra , Elena Issoglio , Giorgio S. Taverna

The Markovian diffusion theory is generalized within the framework of the special theory of relativity using a modification of the mathematical calculus of diffusion on Riemannian manifolds (with definite metric) to describe diffusion on…

Mathematical Physics · Physics 2013-05-29 Joachim Herrmann

A class of Laplace transforms is examined to show that particular cases of this class are associated with production-destruction and reaction-diffusion problems in physics, study of differences of independently distributed random variables…

Classical Analysis and ODEs · Mathematics 2009-11-11 A. M. Mathai , R. K. Saxena , H. J. Haubold

A Lagrangian numerical scheme for solving nonlinear degenerate Fokker-Planck equations in space dimensions $d\ge2$ is presented. It applies to a large class of nonlinear diffusion equations, whose dynamics are driven by internal energies…

Numerical Analysis · Mathematics 2018-06-18 José A. Carrillo , Bertram Düring , Daniel Matthes , David S. McCormick

Based on the non-Markov diffusion equation taking into account the spatial fractality and modeling for the generalized coefficient of particle diffusion…

Statistical Mechanics · Physics 2024-06-19 P. Kostrobij , M. Tokarchuk , B. Markovych , I. Ryzha

This is a review of statistical inference methodology for stochastic differential equations driven by fractional Brownian motion, otherwise called fractional diffusions. The first section reviews the theory needed to rigorously define them.…

Probability · Mathematics 2026-04-07 Pablo Ramses Alonso-Martin , Horatio Boedihardjo , Anastasia Papavasiliou

The present work provides a critical assessment of numerical solutions of the space-fractional diffusion-advection equation, which is of high significance for applications in various natural sciences. In view of the fact that, in contrast…

Statistical Mechanics · Physics 2014-10-27 Robin Stern , Frederic Effenberger , Horst Fichtner , Tobias Schaefer

We obtain explicit expressions for one unknown thermal coefficient (among the conductivity, mass density, specific heat and latent heat of fusion) of a semi-infinite material through the one-phase fractional Lam\'e-Clapeyron-Stefan problem…

Analysis of PDEs · Mathematics 2015-09-15 Domingo Alberto Tarzia

The time-fractional diffusion-wave equation is revisited, where the time derivative is of order $2 \nu$ and $0 < \nu \le 1$. The behaviour of the equation is "diffusion-like" (respectively, "wave-like") when $0 < \nu \le \frac{1}{2}$…

Analysis of PDEs · Mathematics 2021-10-25 Marianito R. Rodrigo

We study problems of the calculus of variations and optimal control within the framework of time scales. Specifically, we obtain Euler-Lagrange type equations for both Lagrangians depending on higher order delta derivatives and…

Optimization and Control · Mathematics 2010-07-30 Rui A. C. Ferreira

In this work, the semi-inverse method has been used to derive the Lagrangian of the Korteweg-de Vries (KdV) equation. Then, the time operator of the Lagrangian of the KdV equation has been transformed into fractional domain in terms of the…

Pattern Formation and Solitons · Physics 2016-08-02 S. A. El-Wakil , E. M. Abulwafa , M. A. Zahran , A. A. Mahmoud

In this paper, we propose a solution of fractional logistic equation by using properties of Mittag-Leffler function.

Classical Analysis and ODEs · Mathematics 2017-02-21 Jignesh P. Chauhan , Ranjan K. Jana , Pratik V. Shah , Ajay K. Shukla

Problems of calculus of variations with variable endpoints cannot be solved without transversality conditions. Here, we establish such type of conditions for fractional variational problems with the Caputo derivative. We consider: the…

Optimization and Control · Mathematics 2015-06-05 Ricardo Almeida , Agnieszka B. Malinowska

This paper deals with an inverse source problem for the $1$D time-fractional diffusion equation by using boundary measurement. The conditional stability in identification of the unknown source term is proved on the basis of the Fourier…

Analysis of PDEs · Mathematics 2016-08-25 Zhiyuan Li

We will give some regularity results about fractional diffusion-wave equations.

Analysis of PDEs · Mathematics 2021-08-10 Paola Loreti , Daniela Sforza

We propose a numerical method for convection-diffusion problems under low regularity assumptions. We derive the method and analyze it using the primal-dual weak Galerkin (PDWG) finite element framework. The Euler-Lagrange formulation…

Numerical Analysis · Mathematics 2024-12-20 Chunmei Wang , Ludmil Zikatanov