English
Related papers

Related papers: Wave equation and dispersion relations for a compr…

200 papers

Motivated by phenomenological questions in quantum gravity, we consider the propagation of a scalar field on a random lattice. We describe a procedure to calculate the dispersion relation for the field by taking a limit of a periodic…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Hanno Sahlmann

We consider a layer of an inviscid fluid with free surface which is subject to vertical high-frequency vibrations. We derive three asymptotic systems of equations that describe slowly evolving (in comparison with the vibration frequency)…

Fluid Dynamics · Physics 2017-11-22 Konstantin Ilin

We investigate the nonlocal behavior of passive tracer dispersion with random stopping at various sites in fluids. This kind of dispersion processes is modeled by an integral partial differential equation, i.e., an advection-diffusion…

Dynamical Systems · Mathematics 2025-10-20 Jinqiao Duan , James R. Brannan , H. Gao

In this paper, we prove some a priori estimates for a system of partial differential equations arising in the nonstationary flow of a nonhomogeneous incompressible asymmetric fluid in a bounded domain with smooth boundary. The unknowns of…

Analysis of PDEs · Mathematics 2018-07-12 Aníbal Coronel , Enrique Fernández-Cara , Marko Rojas-Medar , Alex Tello

The asymptotic derivation of a new family of one-dimensional, weakly nonlinear and weakly dispersive equations that model the flow of an ideal fluid in an elastic vessel is presented. Dissipative effects due to the viscous nature of the…

Fluid Dynamics · Physics 2020-02-20 Dimitrios Mitsotakis , Denys Dutykh , Li Qian

When considering fractional diffusion equation as model equation in analyzing anomalous diffusion processes, some important parameters in the model, for example, the orders of the fractional derivative or the source term, are often unknown,…

Analysis of PDEs · Mathematics 2019-04-15 Zhiyuan Li , Masahiro Yamamoto

We develop a covariant formalism to study nonlinear perturbations of dissipative and interacting relativistic fluids. We derive nonlinear evolution equations for various covectors defined as linear combinations of the spatial gradients of…

Astrophysics · Physics 2009-11-11 David Langlois , Filippo Vernizzi

Distributed order fractional model of viscoelastic body is used in order to describe wave propagation in infinite media. Existence and uniqueness of fundamental solution to the generalized Cauchy problem, corresponding to fractional wave…

Mathematical Physics · Physics 2019-03-12 Sanja Konjik , Ljubica Oparnica , Dusan Zorica

This study handles spatial three-dimensional solution of the nonlinear diffusion equation without particular initial conditions. The functional behavior of the equation and the concentration have been studied in new ways. An auxiliary…

General Mathematics · Mathematics 2020-03-16 Henrik Stenlund

Two questions related to elastic motions are raised and addressed. First: in which theoretical framework can the equations of motion be written for an elastic half-space put into uniform rotation? It is seen that nonlinear finite elasticity…

Soft Condensed Matter · Physics 2013-06-04 Michel Destrade , Giuseppe Saccomandi

We study invariant solutions of a certain class of time-fractional diffusion-wave equations with variable coefficients via Lie symmetry analysis. In physics, the fractional diffusion equation describes transport dynamics that are governed…

In this work we study wave propagation in dissipative relativistic fluids described by a simplified set of the 2nd order viscous conformal hydrodynamic equations. Small amplitude waves are studied within the linearization approximation…

Nuclear Theory · Physics 2015-02-27 D. A. Fogaça , H. Marrochio , F. S. Navarra , J. Noronha

Fractional calculus has been used to describe physical systems with complexity. Here, we show that a fractional calculus approach can restore or include complexity in any physical systems that can be described by partial differential…

Mesoscale and Nanoscale Physics · Physics 2024-08-06 Kyle Rockwell , Ezio Iacocca

The fractional diffusion equation is rigorously derived as a scaling limit from a deterministic Rayleigh gas, where particles interact via short range potentials with support of size $\varepsilon$ and the background is distributed in space…

Analysis of PDEs · Mathematics 2025-11-04 Karsten Matthies , Theodora Syntaka

Colloidal dispersions are commonly encountered in everyday life and represent an important class of complex fluid. Of particular significance for many commercial products and industrial processes is the ability to control and manipulate the…

Soft Condensed Matter · Physics 2010-08-30 J. M. Brader

We study a system of partial differential equations with integer and fractional derivatives arising in the study of forced oscillatory motion of a viscoelastic rod. We propose a new approach considering a quotient of relations appearing in…

Mathematical Physics · Physics 2015-08-11 Teodor M. Atanackovic , Stevan Pilipovic , Dusan Zorica

For any kind of wave phenomenon one can find ways to derive the respective dispersion relation from experimental observations and measurements. This dispersion relation determines the structure of the wave equation and thus characterizes…

Fluid Dynamics · Physics 2026-01-21 Gerd Leuchs , Mojdeh S. Najafabadi

Various forms of derivative dispersion relations, in which the dispersion integral is replaced by a series of derivatives of the imaginary part of a scattering amplitude, are reviewed. Conditions of their validity and practical…

High Energy Physics - Theory · Physics 2007-05-23 Pavel Kolar , Jan Fischer

We examine the applicability of the weak wave turbulence theory in explaining experimental scaling results obtained for the diffusion and relative diffusion of particles moving on turbulent surface waves. For capillary waves our theoretical…

Chaotic Dynamics · Physics 2007-09-23 Victor M. Eguiluz , Mogens T. Levinsen , Preben Alstrom

Explicit analytical expressions for the drag and diffusion coefficients of a spherical particle attached to the interface between two immiscible fluids are constructed for the case of a small viscosity ratio between the fluid phases. The…

Soft Condensed Matter · Physics 2016-04-20 Aaron Dörr , Steffen Hardt