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Combining the tools for transforming space-time developed for General Relativity with the capabilities of artificially structured metamaterials, an entirely new means of controlling electromagnetic fields has emerged. Here, we utilize a…

Concealing an object from incoming waves (light and/or sound) remained science fiction for a long time due to the absence of wave-shielding materials in nature. Yet, the invention of artificial materials and new physical principles for…

Applied Physics · Physics 2021-02-17 Waqas W. Ahmed , Mohamed Farhat , Xiangliang Zhang , Ying Wu

In past years, triggered by their successful realizations in electromagnetics, invisible cloaks have experienced rapid development and have been widely pursued in many different fields, though so far only for a single physical system. In…

Classical Physics · Physics 2015-06-19 Yungui Ma , Yichao Liu , Muhammad Raza , Yudong Wang , Sailing He

In this paper we describe a numerical framework for achieving passive thermal cloaking of arbitrary shapes in both static and transient regimes. The design strategy is cast as the solution of an optimal control problem (OCP) for the heat…

Optimization and Control · Mathematics 2024-06-11 Riccardo Saporiti , Carlo Sinigaglia , Andrea Manzoni , Francesco Braghin

Invisibility devices based on coordinate transformation have opened up a new field of considerable interest. Such a device is proposed to render the hidden object undetectable under the flow of light or sound, by guiding and controlling the…

Optics · Physics 2015-05-20 Shu Zhang , Chunguang Xia , Nicholas Fang

Electromagnetic wave behaviour in an anisotropic medium with a two dimensional arbitrary geometry is studied. The aim is to trace the path of a ray in such a complex medium for the purpose of achieving cloaking (invisibility). A coordinate…

Optics · Physics 2015-11-30 H. H. Sidhwa , R. P. Aiyar , S. V. Kulkarni

Non-reciprocal systems have been shown to exhibit various interesting wave phenomena, such as the non-Hermitian skin effect, which causes accumulation of modes at boundaries. Recent research on discrete systems showed that this effect can…

Applied Physics · Physics 2025-07-24 Felix Langfeldt , Joe Tan , Sayan Jana , Lea Sirota

The synthesis of non-magnetic 2D dielectric cloaks as proper solutions of an inverse scattering problem is addressed in this paper. Adopting the relevant integral formulation governing the scattering phenomena, analytic and numerical…

Classical Physics · Physics 2017-06-29 Loreto Di Donato , Tommaso Isernia , Giuseppe Labate , Ladislau Matekovits

The onset of transformation optics has opened avenues for designing of a plenitude of applications related to propagation of electromagnetic waves in anisotropic media. In this paper, an algorithm is proposed using a coordinate…

Optics · Physics 2015-11-30 H. H. Sidhwa , R. P. Aiyar , S. V. Kulkarni

Based on a coordinate transformation approach, Pendry {\it et al.} have reported electromagnetically anisotropic and inhomogeneous shells that, in theory, completely shield an interior structure of arbitrary size from electromagnetic fields…

It has recently been shown theoretically that the time-dependent heat conduction equation is form-invariant under curvilinear coordinate transformations. Thus, in analogy to transformation optics, fictitious transformed space can be mapped…

Materials Science · Physics 2013-05-14 Robert Schittny , Muamer Kadic , Sebastien Guenneau , Martin Wegener

Love waves are antiplane elastic waves which propagate along the surface of a heterogeneous medium. Under time-harmonic regime, they are governed by a scalar equation of the Helmholtz type. We exploit the invariance of this governing…

Applied Physics · Physics 2023-04-14 Z. Chatzopoulos , A. Palermo , S. Guenneau , A. Marzani

Time-varying guiding structures introduce an additional degree of freedom, besides spatial-variation, that enables better control over the guided wave in a device. Periodically time-modulated structures which are usually considered enable…

Applied Physics · Physics 2020-04-22 Yakir Hadad , Amir Shlivinski

We present a theory for the cloaking of arbitrarily-shaped objects and demonstrate electromagnetic scattering-cancellation through designed homogeneous coatings. First, in the small-particle limit, we expand the dipole moment of a coated…

Mesoscale and Nanoscale Physics · Physics 2014-05-26 Carlo Forestiere , Luca Dal Negro , Giovanni Miano

It is an interesting open problem to achieve adaptive prescribed-time control for strict-feedback systems with unknown and fast or even abrupt time-varying parameters. In this paper we present a solution with the aid of several design and…

Systems and Control · Electrical Eng. & Systems 2022-10-25 Hefu Ye , Yongduan Song

Fundamental features of rotationally symmetric acoustic cloaks with anisotropic inertia are derived. Two universal relations are found to connect the radial and transverse phase speeds and the bulk modulus in the cloak. Perfect cloaking…

Fluid Dynamics · Physics 2008-02-07 Andrew N. Norris

This paper is concerned with the invisibility cloaking in acoustic wave scattering from a new perspective. We are especially interested in achieving the invisibility cloaking by completely regular and isotropic mediums. It is shown that an…

Analysis of PDEs · Mathematics 2016-04-20 Xia Ji , Hongyu Liu

Here we extend the theory of space-time or event cloaking into that based on the carpet or ground-plane reflective surface. Further, by recasting and generalizing a scalar acoustic wave model into a new mathematically covariant form, we…

Optics · Physics 2015-04-27 Paul Kinsler , Martin W. McCall

Living things enact control of non-equilibrium, dynamical structures through complex biochemical networks, accomplishing spatiotemporally-orchestrated physiological tasks such as cell division, motility, and embryogenesis. While the exact…

The ability to create linear systems that manifest broadband nonreciprocal wave propagation would provide for exquisite control over acoustic signals for electronic filtering in communication and noise control. Until now, acoustic…

Applied Physics · Physics 2020-08-26 Aritra Sasmal , Nathan Geib , Karl Grosh