English
Related papers

Related papers: Diffuse wave density and directionality in anisotr…

200 papers

Diffusion-attenuated MR signal for heterogeneous media has been represented as a sum of signals from anisotropic Gaussian sub-domains. Any effect of macroscopic (global or ensemble) anisotropy in the signal can be removed by averaging the…

Applied Physics · Physics 2020-01-03 Magnus Herberthson , Cem Yolcu , Hans Knutsson , Carl-Fredrik Westin , Evren Özarslan

We consider the scattering of elastic waves by highly oscillating anisotropic periodic media with bounded support. Applying the two-scale homogenization, we first obtain a constant coefficient second-order partial differential elliptic…

Analysis of PDEs · Mathematics 2018-02-06 Yi-Hsuan Lin , Shixu Meng

There is an increasing interest in the study of metamaterials and periodic materials across disciplines. These are anisotropic and their properties present directionality. For example, the wave speed depends on the propagation direction.…

Applied Physics · Physics 2023-07-06 Nicolás Guarín-Zapata , Camilo Valencia , Juan Gómez

We study two-dimensional wave propagation in materials whose properties vary periodically in one direction only. High order homogenization is carried out to derive a dispersive effective medium approximation. One-dimensional materials with…

Numerical Analysis · Mathematics 2014-09-16 Manuel Quezada de Luna , David I. Ketcheson

We investigate the reflection and refraction behaviors of electromagnetic waves at the interface between an isotropic material and the anisotropic medium with a unique dispersion relation. We show that the refraction angle of whether phase…

Optics · Physics 2009-11-11 Weixing Shu , Hailu Luo , Fei Li , Zhongzhou Ren

We probe the diffusive motion of particles in slowly sheared three dimensional granular suspensions. For sufficiently large strains, the particle dynamics exhibits diffusive Gaussian statistics, with the diffusivity proportional to the…

Soft Condensed Matter · Physics 2015-06-11 Elie Wandersman , Joshua A. Dijksman , Martin van Hecke

The diffusion of atoms and molecules in ices covering dust grains in dense clouds in interstellar space is an important but poorly characterized step in the formation of complex molecules in space. Here we report the measurement of…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Jiao He , SM Emtiaz , Gianfranco Vidali

If a dissipative anisotropic dielectric material, characterized by the permittivity matrix $\underline{\underline{\epsilon}}$, supports Voigt-wave propagation, then so too does the analogous active material characterized by the permittivity…

Optics · Physics 2017-07-06 Tom G. Mackay , Akhlesh Lakhtakia

We show that a unified and maximally generalized approach to spatial transformation design is possible, one that encompasses all second order waves, rays, and diffusion processes in anisotropic media. Until the final step, it is unnecessary…

Classical Physics · Physics 2018-05-04 Paul Kinsler , Martin W. McCall

We present experimental results on hydrothermal waves in long and narrow 1D channels. In a bounded channel, we describe the primary and secondary instabilities leading to waves and modulated waves in terms of convective/absolute…

Pattern Formation and Solitons · Physics 2009-11-07 Nicolas Garnier , Arnaud Chiffaudel , Francois Daviaud

The present work investigates some exact solutions of the gravitational wave equation in some widely used cosmological spacetimes. The examples are taken from spatially flat and closed isotropic models as well as Kasner metric which is…

General Relativity and Quantum Cosmology · Physics 2021-07-06 Sushovan Mondal , Saif Ali , Shanima S , Narayan Banerjee , Golam Mortuza Hossain

Density is the turbulence statistics that is most readily available from observations. Different regimes of turbulence correspond to different density spectra. For instance, the viscosity-damped regime of MHD turbulence relevant, for…

Astrophysics · Physics 2008-01-03 A. Lazarian , G. Kowal , A. Beresnyak

Anisotropic diffusion processes emerge in various fields such as transport in biological tissue and diffusion in liquid crystals. In such systems, the motion is described by a diffusion tensor. For a proper characterization of processes…

Data Analysis, Statistics and Probability · Physics 2013-11-14 Mario Heidernätsch , Michael Bauer , Günter Radons

The distributions of the angular transmission coefficient and of the total transmission are calculated for multiple scattered waves. The calculation is based on a mapping to the distribution of eigenvalues of the transmission matrix. The…

Condensed Matter · Physics 2009-10-22 Th. M. Nieuwenhuizen , M. C. W. van Rossum

We derive a general theory of effective properties in metasolids based on phononic crystals with low frequency resonances. We demonstrate that in general these structures need to be described by means of a frequency-dependent and non-local…

Materials Science · Physics 2015-12-09 Daniel Torrent , Yan Pennec , Bahram Djafari-Rouhani

A problem of density matrix determination in terms of the given angular distribution of decay products is considered.

High Energy Physics - Phenomenology · Physics 2007-05-23 I. N. Nikitin

We study the tensorial modes of the two-fluid model, where one of this fluids has an equation of state $p = - \rho/3$ (variable cosmological constant, cosmic string fluid, texture) or $p = - \rho$ (cosmological constant), while the other…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. C. Fabris , S. V. B. Goncalves

Convenient variational formula for collective diffusion of many particles adsorbed at lattices of arbitrary geometry is formulated. The approach allows to find the expressions for the diffusion coefficient for any value of the system's…

Statistical Mechanics · Physics 2018-07-04 Marcin Mińkowski , Magdalena A. Załuska--Kotur

The problem of determining the effective conductivity tensor of a magnetoactive turbulent plasma is considered in the approximation of isolated particles. Additional gyrotropicterms are shown to appear in the conductivity tensor in the…

Plasma Physics · Physics 2009-11-10 Otto G. Chkhetiani

Generalizing recent work on isotropic tensor fields in isotropic and achiral condensed matter systems from two to arbitrary dimensions we address both mathematical aspects assuming perfectly isotropic systems and applications focusing on…

Soft Condensed Matter · Physics 2024-10-22 J. P. Wittmer