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In this paper, we consider two regularized transformation-optics cloaking schemes for electromagnetic (EM) waves. Both schemes are based on the blowup construction with the generating sets being, respectively, a generic curve and a planar…

Analysis of PDEs · Mathematics 2016-09-21 Youjun Deng , Hongyu Liu , Gunther Uhlmann

In this work, we find novel static and spherically symmetric wormhole geometries using a three-form field. By solving the gravitational field equations, we find a variety of analytical and numerical solutions and show that it is possible…

General Relativity and Quantum Cosmology · Physics 2018-08-10 Bruno J. Barros , Francisco S. N. Lobo

Traversable wormholes (TWHs) remain one of the most intriguing predictions of General Relativity (GR), offering passage through space-time. However, their existence requires the violation of the null energy condition, making their detection…

General Relativity and Quantum Cosmology · Physics 2025-09-18 Subenoy Chakraborty , Madhukrishna Chakraborty

It is generally agreed that the acceleration of the Universe can best be explained by the presence of dark or phantom energy. The equation of state of the latter shows that the null energy condition is violated. Such a violation is the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Mubasher Jamil , Peter K. F. Kuhfittig , Farook Rahaman , Sk. A Rakib

Noncommutative geometry, an offshoot of string theory, replaces point-like particles by smeared objects. These local effects have led to wormhole solutions in a semiclassical setting, but it has also been claimed that the noncommutative…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Peter K. F. Kuhfittig

The control of magnetic fields, essential for our science and technology, is currently achieved by magnetic materials with positive permeability, including ferromagnetic, paramagnetic, and diamagnetic types. Here we introduce materials with…

Materials Science · Physics 2018-03-22 Rosa Mach-Batlle , Albert Parra , Jordi Prat-Camps , Sergi Laut , Carles Navau , Alvaro Sanchez

In this letter, we propose a conceptual device to perform subwavelength imaging with positive refraction. The key to this proposal is that a drain is no longer a must for some cases. What's more, this device is an isotropic omnidirectional…

Optics · Physics 2015-06-05 Qiannan Wu , Yadong Xu , Huanyang Chen

Magnetism is very important in science and technology, from magnetic recording to energy generation to trapping cold atoms. Physicists have managed to master magnetism - to create and manipulate magnetic fields- almost at will.…

Superconductivity · Physics 2015-05-28 Alvaro Sanchez , Carles Navau , Jordi Prat , Du-Xing Chen

To explain Gamma Ray Bursts, Ruffini argued that the event horizon of a charged black hole is surrounded by a special region called, the Dyadosphere where electric field exceeds the critical value for $e^+$ $e^-$ pair production. In the…

General Relativity and Quantum Cosmology · Physics 2009-02-10 F. Rahaman , M. Kalam , K A Rahman

A unified framework for black holes and traversible wormholes is described, where both are locally defined by outer trapping horizons, two-way traversible for wormholes and one-way traversible for black or white holes. In a two-dimensional…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sean A. Hayward

This paper investigated the viable traversable wormhole solutions through Karmarkar condition in the context of $f(\mathcal{G},T)$ theory. A static spherical spacetime with anisotropic matter configuration is used to study the wormhole…

General Relativity and Quantum Cosmology · Physics 2024-04-30 M. Zeeshan Gul , M. Sharif

Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the…

Optics · Physics 2010-05-03 Qiang Cheng , Tie Jun Cui , Wei Xiang Jiang , Ben Geng Cai

There are hints that the connectivity of space-time in quantum gravity could emerge from entanglement, and it has further been proposed that any two entangled particles may be connected by a quantum wormhole. One way to test this proposal…

General Relativity and Quantum Cosmology · Physics 2021-08-27 Edward Wilson-Ewing

All known solutions to the Einstein equations describing rotating cylindrical wormholes lack asymptotic flatness and therefore cannot describe wormhole entrances as local objects in our Universe. To overcome this difficulty, wormhole…

General Relativity and Quantum Cosmology · Physics 2019-05-13 K. A. Bronnikov , V. G. Krechet

It is well known that solutions of general relativity which allow for traversable wormholes require the existence of exotic matter (matter that violates weak or null energy conditions [WEC or NEC]). In this article, we provide a class of…

General Relativity and Quantum Cosmology · Physics 2009-05-29 F. Rahaman , M. Kalam , K. A. Rahman

The experimental realization of cloaks for electromagnetic fields has been possible only in reduced schemes because of extreme material conditions required in exact cloaks. Here we analytically demonstrate that a simple arrangement of two…

Superconductivity · Physics 2011-12-14 Carles Navau , Jordi Prat-Camps , Alvaro Sanchez

In this paper, we propose a new electromagnetic (EM) GL double layered cloak. The GL double layered cloak is consist of two sphere annular layers, $R_1 \le r \le R_2$ and $R_2 \le r \le R_3$. Two type cloak materials are proposed and…

Optics · Physics 2009-04-22 Ganquan Xie , Jianhua Li , Feng Xie , Lee Xie

While practical realizations of optical invisibility have been achieved so far by various ingenious methods, they generally rely on complex materials which prevent the wide implementation of such schemes. Here, we propose an alternative…

Optics · Physics 2018-12-17 Zeki Hayran , Ramon Herrero , Muriel Botey , Hamza Kurt , Kestutis Staliunas

Concealing objects by making them invisible to an external electromagnetic probe is coined by the term cloaking. Cloaking devices, having numerous potential applications, are still face challenges in realization, especially in the visible…

We study the properties of an artificial electromagnetic black hole for transverse magnetic modes rigorously. A multi-layered structure of such a black hole is then proposed as a reduced variety for easy experimental realizations. An actual…

Optics · Physics 2015-05-18 Wanli Lu , JunFeng Jin , Huanyang Chen , Zhifang Lin