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A time-domain numerical code based on the constitutive relations of nonlinear acoustics for simulating ultrasound propagation is presented. To model frequency power law attenuation, such as observed in biological media, multiple relaxation…

We propose an extension of the cable equation by introducing a Caputo time fractional derivative. The fundamental solutions of the most common boundary problems are derived analitically via Laplace Transform, and result be written in terms…

Biological Physics · Physics 2017-05-19 Silvia Vitali , Gastone Castellani , Francesco Mainardi

In this paper we investigate the following fractional order in time Cauchy problem \begin{equation*} \begin{cases} \mathbb{D}_{t}^{\alpha }u(t)+Au(t)=f(u(t)), & 1<\alpha <2, u(0)=u_{0},\,\,\,u^{\prime }(0)=u_{1}. & \end{cases}%…

Analysis of PDEs · Mathematics 2018-08-08 Edgardo Alvarez , Ciprian Gal , Valentin Keyantuo , Mahamadi Warma

We review some fractional free boundary problems that were recently considered for modeling anomalous phase-transitions. All problems are of Stefan type and involve fractional derivatives in time according to Caputo's definition. We survey…

Analysis of PDEs · Mathematics 2020-02-18 Andrea N. Ceretani

We present an exponentially convergent numerical method to approximate the solution of the Cauchy problem for the inhomogeneous fractional differential equation with an unbounded operator coefficient and Caputo fractional derivative in…

Numerical Analysis · Mathematics 2025-04-08 Dmytro Sytnyk , Barbara Wohlmuth

We consider the initial-value problem of abstract wave equations with weak dissipation. We show that under conditions on the dissipation coefficient and its derivative the solutions to the abstract dissipative equation are closely related…

Analysis of PDEs · Mathematics 2007-11-15 Jens Wirth

Attenuation of ultrasound often follows near power laws which cannot be modeled with conventional viscous or relaxation wave equations. The same is often the case for shear wave propagation in tissue also. More general temporal memory…

Classical Physics · Physics 2016-11-18 Sverre Holm

In this paper, we propose a novel machine learning method based on adaptive tensor neural network subspace to solve linear time-fractional diffusion-wave equations and nonlinear time-fractional partial integro-differential equations. In…

Machine Learning · Computer Science 2025-10-10 Zhongshuo Lin , Qingkui Ma , Hehu Xie , Xiaobo Yin

This work is dedicated to the study of a mixed-type partial differential equation involving a Caputo fractional derivative in the time domain $t > 0$ and a classical parabolic equation in the domain $t < 0$, along with Dezin-type non-local…

Analysis of PDEs · Mathematics 2025-07-17 Ravshan Ashurov , Umida Dusanova , Navbahor Nuraliyeva

A modification of the Drude dispersive model based on fractional time derivative is presented. The dielectric susceptibility is calculated analytically and simulated numerically, showing a good agreement between theoretical description and…

Computational Physics · Physics 2021-03-23 Karol Karpiński , Sylwia Zielińska - Raczyńska , David Ziemkiewicz

This work concerns causal acoustical wave equations which imply frequency power-law attenuation. A connection between the five-parameter fractional Zener wave equation, which is derived from a fractional stress-strain relation plus…

Mathematical Physics · Physics 2012-04-24 Sven Peter Näsholm , Sverre Holm

The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we derive and analyze causal equations describing propagation of…

Mathematical Physics · Physics 2011-12-06 Kowar Richard , Scherzer Otmar , Bonnefond Xavier

In this article, we deal with fractional stochastic differential equations, so-called Caputo type fractional backward stochastic differential equations (Caputo fBSDEs, for short), and study the well-posedness of an adapted solution to…

Probability · Mathematics 2022-10-05 Nazim I. Mahmudov , Arzu Ahmadova

In this paper invariant subspace method has been employed for solving linear and non-linear fractional partial differential equations involving Caputo derivative. A variety of illustrative examples are solved to demonstrate the…

Analysis of PDEs · Mathematics 2017-04-18 Sangita Choudhary , Varsha Daftardar-Gejji

We develop a fully discrete scheme for time-fractional diffusion equations by using a finite difference method in time and a finite element method in space. The fractional derivatives are used in Caputo sense. Stability and error estimates…

Analysis of PDEs · Mathematics 2019-08-05 Moulay Rchid Sidi Ammi , Ismail Jamiai , Delfim F. M. Torres

Diffusive representations of fractional derivatives have proven to be useful tools in the construction of fast and memory efficient numerical methods for solving fractional differential equations. A common challenge in many of the known…

Numerical Analysis · Mathematics 2022-04-11 Kai Diethelm

The paper presents two representative classes of Impulsive Fractional Differential Equations defined with generalized Caputo\'s derivative, with fixed lower limit and changing lower limit, respectively. Memory principle is studied and…

Chaotic Dynamics · Physics 2024-07-17 Marius-F. Danca , Michal feckan

In this paper, we propose a fractional time extension of the Quan tum Master Equation. We introduce a Caputo-type fractional derivative in time as an extension of the exponential decay of the Lindblad framework through the incorporation of…

Quantum Physics · Physics 2025-12-22 Taylan Demir

We introduce a method which provides accurate numerical solutions to fractional-in-time partial differential equations posed on $[0,T] \times \Omega$ with $\Omega \subset \mathbb{R}^d$ without the excessive memory requirements associated…

Numerical Analysis · Mathematics 2023-10-12 Timon S. Gutleb , José A. Carrillo

We develop the theory of fractional gradient flows: an evolution aimed at the minimization of a convex, l.s.c.~energy, with memory effects. This memory is characterized by the fact that the negative of the (sub)gradient of the energy equals…

Analysis of PDEs · Mathematics 2021-01-05 Wenbo Li , Abner J. Salgado