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Cloaking is a method of making obstacles undetectable. Here we cloak unit cells of a magnetic pattern squeezed into an otherwise periodic pattern from a magnetically driven colloidal flow. We apply a time-periodic external magnetic field…

We develop a very general theory on the regularized approximate invisibility cloaking for the wave scattering governed by the Helmholtz equation in any space dimensions via the approach of transformation optics.

Analysis of PDEs · Mathematics 2015-03-04 Jingzhi Li , Hongyu Liu , Luca Rondi , Gunther Uhlmann

Cloaking elastic waves has, in contrast to the cloaking of electromagnetic waves, remained a fundamental challenge: the latter successfully uses the invariance of Maxwell's equations, from which the field of transformational optics has…

Materials Science · Physics 2020-11-17 Davide Enrico Quadrelli , Richard Craster , Muamer Kadic , Francesco Braghin

Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking. To achieve spatial cloaking, the index of refraction is manipulated to flow…

The approximate cloaking is investigated for time-harmonic Maxwell's equations via the approach of transformation optics. The problem is reduced to certain boundary effect estimates due to an inhomogeneous electromagnetic inclusion with an…

Analysis of PDEs · Mathematics 2013-05-10 Gang Bao , Hongyu Liu

Transformation optics constructions have allowed the design of electromagnetic, acoustic and quantum parameters that steer waves around a region without penetrating it, so that the region is hidden from external observations. The material…

Optics · Physics 2009-11-13 A. Greenleaf , Y. Kurylev , M. Lassas , G. Uhlmann

We study the approximate cloaking via transformation optics for electromagnetic waves in the time harmonic regime in which the cloaking device {\it only} consists of a layer constructed by the mapping technique. Due to the fact that…

Analysis of PDEs · Mathematics 2018-11-02 Hoai-Minh Nguyen , Loc Tran

The concept of cloaking -- hiding objects from external detection -- has seen wide success in linear systems. Yet, translating these advancements to nonlinear mechanical systems remains an open challenge. Here, we present a new approach to…

The regularized near-cloak via the transformation optics approach in the time-harmonic electromagnetic scattering is considered. This work extends the existing studies mainly in two aspects. First, it presents a near-cloak construction by…

Analysis of PDEs · Mathematics 2013-05-10 Gang Bao , Hongyu Liu , Jun Zou

An acoustic cloak envelopes an object so that sound incident from all directions passes through and around the cloak as though the object were not present. A theory of acoustic cloaking is developed using the transformation or…

Materials Science · Physics 2008-07-13 Andrew N. Norris

In this work, we develop a general mathematical framework on regularized approximate cloaking of elastic waves governed by the Lam\'e system via the approach of transformation elastodynamics. Our study is rather comprehensive. We first…

Analysis of PDEs · Mathematics 2014-10-10 Guanghui Hu , Hongyu Liu

The aim of this paper is to extend the method of improving cloaking structures in the conductivity to scattering problems. We construct very effective near-cloaking structures for the scattering problem at a fixed frequency. These new…

Analysis of PDEs · Mathematics 2015-05-30 Habib Ammari , Hyeonbae Kang , Hyundae Lee , Mikyoung Lim

We consider approximate cloaking from a regularization viewpoint introduced in [13] for EIT and further investigated in [12] [17] for the Helmholtz equation. The cloaking schemes in [12] and [17] are shown to be (optimally) within…

Analysis of PDEs · Mathematics 2015-05-30 Jingzhi Li , Hongyu Liu , Hongpeng Sun

We report on a new concept of cloaking objects in diffusive light regime using the paradigm of the scattering cancellation and mantle cloaking techniques. We show numerically that an object can be made completely invisible to diffusive…

Transformation optics constructions have allowed the design of cloaking devices that steer electromagnetic, acoustic and quantum waves around a region without penetrating it, so that this region is hidden from external observations. The…

Analysis of PDEs · Mathematics 2015-09-15 Matti Lassas , Ting Zhou

A new recipe for concealing objects from detection is suggested. Different with traditional cloak which deflects light around the core of the cloak to make the object inside invisible, our cloak guides the light to penetrate the core of the…

Optics · Physics 2008-08-05 Yu Luo , Jingjing Zhang , Hongsheng Chen , Bae-Ian Wu , Jin Au Kong

In this paper, we consider the approximate acoustic cloaking in inhomogeneous isotropic background space. By employing transformation media, together with the use of a sound-soft layer lining right outside the cloaked region, we show that…

Analysis of PDEs · Mathematics 2012-05-01 Hongyu Liu

The invariance under co-ordinate transformations of a set of partial differential equations can lead to the possibility of invisibility cloaking, whereby an anomaly in the interior of a body is shielded from an external observer. The form…

Classical Physics · Physics 2019-03-18 F. Syvret , D. Al-Attar

We consider regularized approximate cloaking for the Helmholtz equation. Various cloaking schemes have been recently proposed and extensively investigated. The existing cloaking schemes in literature are (optimally) within $|\ln\rho|^{-1}$…

Analysis of PDEs · Mathematics 2012-07-04 Hongyu Liu , Hongpeng Sun

In this article we consider cloaking for a quasi-linear elliptic partial differential equation of divergence type defined on a bounded domain in $\mathbb{R}^N$ for $N=2,3$. We show that a perfect cloak can be obtained via a singular change…

Analysis of PDEs · Mathematics 2019-08-01 Tuhin Ghosh , Karthik Iyer
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