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Related papers: Shedding Light on Naked Singularities

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We investigate the occurrence and nature of naked singularities in the Szekeres space-times. These space-times represent irrotational dust. They do not have any Killing vectors and they are generalisations of the Tolman-Bondi-Lemaitre…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Pankaj S. Joshi , Andrzej Krolak

We follow the trajectories of phase singularities at nulls of intensity in the speckle pattern of waves transmitted through random media as the frequency of the incident radiation is scanned in microwave experiments and numerical…

Disordered Systems and Neural Networks · Physics 2015-06-19 Xiaojun Cheng , Yitzchak Lockerman , Azriel Z. Genack

We propose a general theoretical scheme for the investigation of light emitted from nano- and micrometric structures of arbitrary shape and composition. More specifically, the proposed fully three-dimensional approach allows to derive the…

Materials Science · Physics 2009-11-07 M. Pieruccini , S. Savasta , R. Girlanda , R. Iotti , F. Rossi

Extremal six-dimensional black string solutions with some non-trivial momentum distribution along the wave are considered. These solutions were recently shown to contain a singularity at the would-be position of the event horizon. In the…

High Energy Physics - Theory · Physics 2010-02-03 Simon F. Ross

In the first quarter of the 20th century, physicists were not aware of the existence of classical electromagnetic zero-point radiation nor of the importance of special relativity. Inclusion of these aspects allows classical electron theory…

Classical Physics · Physics 2022-01-11 Timothy H. Boyer

Electronic matter waves traveling through the weak and smoothly varying disorder potential of a semi-conductor show branching behavior instead of a smooth spreading of flow. By transferring this phenomenon to optics, we show how the…

It is now theoretically well established that not only a black hole can cast shadow, but other compact objects such as naked singularities, gravastar or boson stars can also cast shadows. An intriguing fact that has emerged is that the…

General Relativity and Quantum Cosmology · Physics 2021-06-25 Kanwar Preet Kaur , Pankaj S. Joshi , Dipanjan Dey , Ashok B. Joshi , Rucha P. Desai

The mathematical notion of a spectral singularity admits a physical interpretation as a zero-width resonance. It finds an optical realization as a certain type of lasing effect that occurs at the threshold gain. We explore spectral…

Mathematical Physics · Physics 2011-10-18 Ali Mostafazadeh , Mustafa Sarisaman

Electromagnetic wave scattering by many parallel infinite cylinders is studied asymptotically as $a\to 0$. Here $a$ is the radius of the cylinders. It is assumed that the points $\hat{x}_m$ are distributed so that…

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

We consider a nonlinear dielectric medium surrounding a static, charged and spherically symmetric compact body which gravitational field is driven by General Relativity (GR). Considering the propagating waves on the dielectric medium, we…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Amanda Guerrieri , Mario Novello

We consider the interaction of atoms with the quantized electromagnetic field in the presence of materials with negative index of refraction. Spontaneous emission of an atom embedded in a negative index material is discussed. It is shown…

Quantum Physics · Physics 2007-05-23 Jürgen Kästel , Michael Fleischhauer

A spherically symmetric collapsing scalar field model is discussed with a dissipative fluid which includes a heat flux. This vastly general matter distribution is analyzed at the expense of a high degree of symmetry in the space-time, that…

General Relativity and Quantum Cosmology · Physics 2017-01-17 Narayan Banerjee , Soumya Chakrabarti

Non-linear electrodynamics coupled to general relativity is investigated. In general relativity, it is observed that the expansion of the universe is accelerating if the source of the gravitational field is the non-linear electromagnetic…

General Relativity and Quantum Cosmology · Physics 2018-10-05 Gauranga C. Samanta , Shantanu K. Biswal , Kazuharu Bamba

We describe one-dimensional stationary scattering of a two-component wave field by a non-Hermitian matrix potential which features odd-$PT$ symmetry, i.e., symmetry with $(PT)^2=-1$. The scattering is characterized by a $4\times 4$ transfer…

Optics · Physics 2019-01-23 Vladimir V. Konotop , Dmitry A. Zezyulin

Repulsive singularities (repulsons) in extended supergravity theories are investigated. These repulsive singularities are related to attractive singularities (black holes) in moduli space of extended supergravity vacua. In order to study…

High Energy Physics - Theory · Physics 2009-10-31 Ingo Gaida

Geometric optics effectively describes the propagation of electromagnetic waves when the wavelength is much smaller than the characteristic length scale of the medium, making wave phenomena like diffraction negligible. As a result, light…

General Relativity and Quantum Cosmology · Physics 2025-02-06 Sebastian Murk , Daniel R. Terno , Rama Vadapalli

Generalizing earlier results of Joshi and Dwivedi (Commun. Math. Phys. 146, 333 (1992); Lett. Math. Phys. 27, 235 (1993)), we analyze here the spherically symmetric gravitational collapse of a matter cloud with a general form of matter for…

General Relativity and Quantum Cosmology · Physics 2009-10-22 I. H. Dwivedi , P. S. Joshi

Nonlinear waves in defocusing media are investigated in the framework of the hydrodynamic description of light as a photon fluid. The observations are interpreted in terms of an emergent curved spacetime generated by the waves themselves,…

General Relativity and Quantum Cosmology · Physics 2015-12-07 Francesco Marino , Calum Maitland , David Vocke , Antonello Ortolan , Daniele Faccio

We consider the motion of a nonrelativistic electron in the field of two strong monochromatic light waves propagating counter to each other. The wave function of the electron is obtained by using a quasiclassical approximation and…

General Physics · Physics 2017-08-21 K. V. Ivanyan

Consider the transverse magnetic polarization of the electromagnetic scattering of a plane wave by a perfectly conducting plane surface, which contains a two-dimensional subwavelength rectangular cavity. The enhancement is investigated…

Analysis of PDEs · Mathematics 2017-11-21 Yixian Gao , Peijun Li , Xiaokai Yuan