In this short review, we present some recently obtained traversable wormhole models in the framework of general relativity (GR) in four and six dimensions that somehow widen our common ideas on wormhole existence and properties. These are, first, rotating cylindrical wormholes, asymptotically flat in the radial direction and existing without exotic matter. The topological censorship theorems are not violated due to lack of asymptotic flatness in all spatial directions. Second, these are cosmological wormholes constructed on the basis of the Lemaître-Tolman-Bondi solution. They connect two copies of a closed Friedmann world filled with dust, or two otherwise distant parts of the same Friedmann world. Third, these are wormholes obtained in six-dimensional GR, whose one entrance is located in 'our' asymptotically flat world with very small extra dimensions while the other 'end' belongs to a universe with large extra dimensions and therefore different physical properties. The possible observable features of such wormholes are briefly discussed. This article is part of the theme issue 'The future of mathematical cosmology, Volume 1'.
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http://dx.doi.org/10.1098/rsta.2021.0176 | DOI Listing |
Entropy (Basel)
November 2024
Terra Quantum AG, Kornhausstrasse 25, 9000 St. Gallen, Switzerland.
We present the Quantum Memory Matrix (QMM) hypothesis, which addresses the longstanding Black Hole Information Paradox rooted in the apparent conflict between Quantum Mechanics (QM) and General Relativity (GR). This paradox raises the question of how information is preserved during black hole formation and evaporation, given that Hawking radiation appears to result in information loss, challenging unitarity in quantum mechanics. The QMM hypothesis proposes that space-time itself acts as a dynamic quantum information reservoir, with quantum imprints encoding information about quantum states and interactions directly into the fabric of space-time at the Planck scale.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA.
High-energy extensions to general relativity modify the Einstein-Hilbert action with higher-order curvature corrections and theory-specific coupling constants. The order of these corrections imprints a universal curvature dependence on observations while the coupling constant controls the deviation strength. In this Letter, we leverage the theory-independent expectation that modifications to the action of a given order in spacetime curvature (Riemann tensor and contractions) lead to observational deviations that scale with the system length scale to a corresponding power.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences, Bartycka 18, 00-716 Warsaw, Poland.
We performed the first simulations of accretion onto the compact objects in the Reissner-Nordström (RN) space-time. The results obtained in general relativity are representative of those for spherically symmetric naked singularities and black holes in a number of modified gravity theories. A possible application of these calculations is to the active galactic nuclei with their powerful jets and outflows.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Fundamentale Physik für Metrologie FPM, Physikalisch-Technische Bundesanstalt PTB, Bundesallee 100, 38116 Braunschweig, Germany.
Motivated by the similarity of the mathematical structure of Einstein's general relativity in its weak field limit and of Maxwell's theory of electrodynamics it is shown that there are gravitational analogs of the Josephson effect and the quantum Hall effect. These effects can be combined to derive a gravitational analogue of the electric quantum metrological triangle. The gravitational quantum metrological triangle may have applications in metrology and could be used to investigate the relation of the Planck constant to fundamental particle masses.
View Article and Find Full Text PDFNat Commun
January 2025
Département de Physique Appliquée, Université de Genève, Genève, Switzerland.
Non-signalling conditions encode minimal requirements that any (quantum) systems must satisfy in order to be consistent with special relativity. Recent works have argued that in scenarios involving more than two parties, correlations compatible with relativistic causality do not have to satisfy all possible non-signalling conditions but only a subset of them. Here we show that correlations satisfying only this subset of constraints have to satisfy highly non-local monogamy relations between the effects of space-like separated random variables.
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