We study the head-on collision of fluid particles well within the kinetic energy dominated regime (γ = 8 to 12) by numerically solving the Einstein-hydrodynamic equations. We find that the threshold for black hole formation is lower (by a factor of a few) than simple hoop conjecture estimates, and, moreover, near this threshold two distinct apparent horizons first form postcollision and then merge. We argue that this can be understood in terms of a gravitational focusing effect. The gravitational radiation reaches luminosities of 0.014 c(5)/G, carrying 16 ± 2% of the total energy.
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http://dx.doi.org/10.1103/PhysRevLett.110.101101 | DOI Listing |
Stud Hist Philos Sci
January 2025
Philosophy Department, Tufts University, United States of America; Black Hole Initiative, Harvard University, United States of America; Lichtenberg Group for History and Philosophy of Physics, University of Bonn, Germany. Electronic address:
In this paper, I provide an account of direct (vs. indirect) detection in gravitational-wave astrophysics. In doing so, I highlight the epistemic considerations that lurk behind existing debates over the application of the term "direct".
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Hainan Engineering Research Center of Tropical Ocean Advanced Optoelectronic Functional Materials, Hainan International Joint Research Center of Marine Advanced Photoelectric Functional Materials, Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Key Laboratory of Functional Materials and Photoelectrochemistry of Haikou, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China.
The CsPbBr perovskite exhibits strong environmental stability under light, humidity, temperature, and oxygen conditions. However, in all-inorganic perovskite solar cells (PSCs), interface defects between the carbon electrode and CsPbBr limit the carrier separation and transfer rates. We used black phosphorus (BP) nanosheets as the hole transport layer (HTL) to construct an all-inorganic carbon-based CsPbBr perovskite (FTO/c-TiO/m-TiO/CsPbBr/BP/C) solar cell.
View Article and Find Full Text PDFOpen Res Eur
January 2025
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, 91125, USA.
The study of transient and variable events, including novae, active galactic nuclei, and black hole binaries, has historically been a fruitful path for elucidating the evolutionary mechanisms of our universe. The study of such events in the millimeter and submillimeter is, however, still in its infancy. Submillimeter observations probe a variety of materials, such as optically thick dust, which are hard to study in other wavelengths.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
EPFL: Ecole Polytechnique Federale de Lausanne, Department of Chemistry, Rue de Industries 17, 1050, Sion, SWITZERLAND.
Carbon perovskite solar cells (C-PSCs) represent a promising photovoltaic technology that addresses the long-term operating stability needed to compete with commercial Si solar cells. However, the poor interface contacts between the carbon electrode and the perovskite result in a gap between C-PSC's performances and state-of-the-art PSCs based on metallic back electrodes. In this work, Cu (II) phthalocyanine (CuPc) was rediscovered as an effective hole-transporting material (HTM) to be coupled with carbon electrodes.
View Article and Find Full Text PDFEntropy (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.
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