Results 51 to 60 of about 35,096 (197)

Geodesically complete black holes in Lorentz-violating gravity

Journal of High Energy Physics, 2022
We present a systematic study of the geometric structure of non-singular spacetimes describing black holes in Lorentz-violating gravity. We start with a review of the definition of trapping horizons, and the associated notions of trapped and marginally ...
Raúl Carballo-Rubio, Francesco Di Filippo, Stefano Liberati, Matt Visser   +3 more
doaj   +1 more source

Quantum Black Holes and (Re)Solution of the Singularity

Universe, 2021
Classical general relativity predicts the occurrence of spacetime singularities under very general conditions. Starting from the idea that the spacetime geometry must be described by suitable states in the complete quantum theory of matter and gravity ...
Roberto Casadio
doaj   +1 more source

Higher dimensional radiation collapse and cosmic censorship [PDF]

, 2000
We study the occurrence of naked singularities in the spherically symmetric collapse of radiation shells in a higher dimensional spacetime. The necessary conditions for the formation of a naked singularity or a black hole are obtained.
A. llha, A. llha, A. Papapetrou, B.C. Nolan, B.R. Iyer, C.J.S. Clarke, F.J. Tipler, I.H. Dwivedi, J.J. Schwarz, J.P.S. Lemos, J.P.S. Lemos, K. Lake, K. Rajagopal, O. Klein, P.C. Vaidya, P.C. Vaidya, P.S. Joshi, R. Penrose, R. V. Saraykar, S. Barve, S. G. Ghosh, S.G. Ghosh, S.S. Deshingkar, T. Kaluza   +23 more
core   +2 more sources

Singular sources in Demiański–Newman spacetimes [PDF]

Classical and Quantum Gravity, 2006
22 pages, 5 figures; submitted to Classical and Quantum ...
Manko, V. S., Martin, J., Ruiz, E.
openaire   +2 more sources

Photonic Time Crystals and Time‐Varying Electromagnetic Metamatter: A New Direction for Ultrafast Tunable Photonic and Microwave Materials and Devices

Advanced Science, EarlyView.
Photonic time crystals (PTCs) are systems in which electromagnetic parameters are modulated periodically in time, producing momentum bandgaps via temporal scattering rather than spatial Bragg processes. This review examines the theoretical frameworks, modeling, and computational tools for time‐varying media, and summarizes experimental demonstrations ...
Ranjan Kumar Patel, Shriram Ramanathan, Ronald P. Jenkins, Michael J. Carter   +3 more
wiley   +1 more source

D-dimensional charged Anti-de-Sitter black holes in f (T) gravity

Journal of High Energy Physics, 2017
We present a D-dimensional charged Anti-de-Sitter black hole solutions in f (T) gravity, where f (T) = T + βT 2 and D ≥ 4. These solutions are characterized by flat or cylindrical horizons.
A.M. Awad, S. Capozziello, G.G.L. Nashed
doaj   +1 more source

Who's Afraid of Naked Singularities?

, 1999
To probe naked spacetime singularities with waves rather than with particles we study the well-posedness of initial value problems for test scalar fields with finite energy so that the natural function space of initial data is the Sobolev space.
A. Ori, Akihiro Ishibashi, Akio Hosoya, C. Gundlach, C. J. S. Clarke, C. J. S. Clarke, D. Christodoulou, D. M. Eardley, F. R. Tangherlini, G. T. Horowitz, G. T. Horowitz, G. W. Gibbons, K. Lake, M. D. Roberts, M. D. Roberts, M. Reed, M. W. Choptuik, M. Wyman, N. D. Birrell, P. R. Brady, P. R. Brady, P. S. Joshi, P. S. Joshi, R. C. Myers, R. M. Wald, R. M. Wald, R. P. A. C. Newman, S. W. Hawking, S. W. Hawking, T. Koike, Y. Oshiro   +30 more
core   +1 more source

Existence of Solutions of Semilinear Wave Equations With Time‐Dependent Propagation Speed and Time Derivative Nonlinearity

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Consider wave equations with time derivative nonlinearity and time‐dependent propagation speed which are generalized versions of the wave equations in the Friedmann–Lemaître–Robertson–Walker (FLRW) spacetime, the de Sitter spacetime and the anti‐de Sitter space time.
Kimitoshi Tsutaya, Yuta Wakasugi
wiley   +1 more source

Deforming black holes with even multipolar differential rotation boundary

Journal of High Energy Physics, 2019
Motivated by the novel asymptotically global AdS4 solutions with deforming horizon in [21], we analyze the boundary metric with even multipolar differential rotation and numerically construct a family of deforming solutions with quadrupolar differential ...
Hong-Bo Li, Tong-Tong Hu, Ben-Shen Song, Shuo Sun, Yong-Qiang Wang   +4 more
doaj   +1 more source

Spherical collapse of inhomogeneous dust cloud in the Lovelock theory

, 2011
We study gravitational collapse of a spherically symmetric inhomogeneous dust cloud in the Lovelock theory without cosmological constant. We show that the final fate of gravitational collapse in this theory depends on the spacetime dimensions.
Jhingan, Sanjay, Ohashi, Seiju, Shiromizu, Tetsuya   +2 more
core   +1 more source