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Let $M$ be the number of bounded and Lipschitz regular obstacles $D_j, j:=1, ..., M$ having a maximum radius $a$, $a<<1$, located in a bounded domain $\Omega$ of $\mathbb{R}^3$. We are concerned with the acoustic scattering problem with a…

Analysis of PDEs · Mathematics 2016-10-20 Bashir Ahmad , Durga Prasad Challa , Mokhtar Kirane , Mourad Sini

We deal with the time-harmonic acoustic waves scattered by a large number of small holes, of maximal radius $a, a<<1$, arbitrary (i.e. not necessarily periodically) distributed in a bounded part of a homogeneous background. We show that as…

Mathematical Physics · Physics 2017-11-15 Durga Prasad Challa , Andrea Mantile , Mourad Sini

Negative refraction of acoustic waves is demonstrated through underwater experiments conducted at ultrasonic frequencies on a 3D locally resonant acoustic metafluid made of soft porous silicone-rubber micro-beads suspended in a yield-stress…

A type of 3-dimensional optical negative-refractive-index metamaterials composed of all dielectric nanospheres is proposed and demonstrated theoretically. The metamaterials are constructeded by pairing together two kinds of dielectric…

A recipe for creating materials with a desired refraction coefficient is implemented numerically. The following assumptions are used: \bee \zeta_m=h(x_m)/a^\kappa,\quad d=O(a^{(2-\kappa)/3}),\quad M=O(1/a^{2-\kappa}),\quad \kappa\in(0,1),…

Numerical Analysis · Mathematics 2010-02-19 Sapto W. Indratno , Alexander G. Ramm

We study the time-domain acoustic scattering problem by a cluster of small holes (i.e. sound-soft obstacles). Based on the retarded boundary integral equation method, we derive the asymptotic expansion of the scattered field as the size of…

Analysis of PDEs · Mathematics 2020-02-17 Mourad Sini , Haibing Wang , Qingyun Yao

Perfect lensing and cloaking based on complementary media are possible applications of negative refractive index materials. Metamaterials represent the natural candidates to realize such property by tailoring the effective dielectric…

Materials Science · Physics 2010-01-31 Claudio Amabile , Enrico Prati

We consider wave propagation across an infinite waveguide of an arbitrary bounded cross-section, whose interior is blocked by two identical thick barriers with holes. When the holes are small, the waves over a broad range of frequencies are…

Mathematical Physics · Physics 2021-10-14 A. Delitsyn , D. S. Grebenkov

We are concerned with the acoustic scattering problem, at a frequency $\kappa$, by many small obstacles of arbitrary shapes with impedance boundary condition. These scatterers are assumed to be included in a bounded domain $\Omega$ in…

Analysis of PDEs · Mathematics 2016-10-20 Durga Prasad Challa , Mourad Sini

We identify a route towards achieving a negative index of refraction at optical frequencies based on coupling between plasmonic waveguides that support backwards waves. We show how modal symmetry can be exploited in metal-dielectric…

Optics · Physics 2015-05-18 Ewold Verhagen , René de Waele , L. , Kuipers , Albert Polman

Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit…

Quantum Physics · Physics 2016-03-07 Florian Pinsker

An analytical model is presented for a rectangular lattice of isotropic scatterers with electric and magnetic resonances. Each isotropic scatterer is formed by putting appropriately 6 $\Omega$-shaped perfectly conducting particles on the…

Optics · Physics 2009-11-07 Constantin R. Simovski , Sailing He

Asymptotic solution to many-body wave scattering problem is given in the case of many small scatterers. The small scatterers can be particles whose physical properties are described by the boundary impedances, or they can be small…

Mathematical Physics · Physics 2011-01-25 A. G. Ramm

Negative-index refraction is achieved in a lamellar composite with epsilon-negative (ENG) and mu-negative (MNG) materials stacked alternatively. Based on the effective medium approximation, simultaneously negative effective permittivity and…

Optics · Physics 2009-11-11 Z. G. Dong , S. N. Zhu , H. Liu

Electromagnetic wave scattering by many parallel to $z-$axis, thin, impedance, circular infinite cylinders is studied asymptotically as $a\to 0$. Let $D_m$ be the crossection of the $m-$th cylinder, $a$ be its radius, and…

Mathematical Physics · Physics 2012-09-03 A. G. Ramm

Geometrically decorated two-dimensional (2D) discrete surfaces can be more effective than conventional smooth reflectors in managing wave radiation. Constructive non-specular wave scattering permits the scattering angle to be other than…

We are considered the propagation of the fundamental and second harmonic solitary waves under the slowly varying envelope pulses approximation in a quadratic nonlinear medium that characterized by negative refraction index at the frequency…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 Andrew I. Maimistov , Ildar R. Gabitov , Elena V. Kazantseva

This paper investigates the problem of time-harmonic acoustic scattering in an inhomogeneous medium with a complex topological structure. Specifically, the medium is anisotropic and contains several disjoint sound-soft obstacles. This model…

Mathematical Physics · Physics 2025-09-30 Huaian Diao , Qingle Meng , Zhiying Sun

We present an efficient method for the design of anomalous reflectors for acoustic waves. The approach is based on the fact that the anomalous reflector is actually a diffraction grating in which the amplitude of all the modes is negligible…

Applied Physics · Physics 2018-08-15 Daniel Torrent

Theory of scattering by many small bodies is developed under various assumptions concerning the ratio $\frac{a}{d}$, where $a$ is the characteristic dimension of a small body and $d$ is the distance between neighboring bodies $d =…

Mathematical Physics · Physics 2009-11-13 A. G. Ramm
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