Results 81 to 90 of about 7,819 (229)

Stochastic Quantum Mechanics in Curved Spaces: Application to Schwarzschild Black Holes

Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT In this work, we start from the hypothesis that the universe lives in a Gravitational Wave Background (GWB). From this hypothesis, it follows that space–time is not locally flat because we have to take into account the fluctuations of the GWB in space–time. This implies that sufficiently small particles will feel these oscillations, preventing
Juan S. Jerez‐Rodriguez, Tonatiuh Matos   +1 more
wiley   +1 more source

The formation of supermassive black holes and the evolution of supermassive stars

Classical and Quantum Gravity, 2001
The existence of supermassive black holes is supported by a growing body of observations. Supermassive black holes and their formation events are likely candidates for detection by proposed long-wavelength, space-based gravitational wave interferometers like LISA.
New, Kimberly C. B., Shapiro, Stuart L.
openaire   +3 more sources

Interplay of Magnetic Reconnection and Current Sheet Kink Instability in the Earth's Magnetotail

Geophysical Research Letters, Volume 52, Issue 2, 28 January 2025.
Abstract Magnetic reconnection and current sheet kink instability often develop concurrently in current sheets, yet their dynamic interplay remains unclear. We investigate their interaction in the magnetotail of a 3D global magnetospheric hybrid‐Vlasov simulation. We identify the instability growth and saturation phase and estimate the evolution of the
G. Cozzani, M. Alho, I. Zaitsev, H. Zhou, S. Hoilijoki, L. Turc, M. Grandin, K. Horaites, M. Battarbee, Y. Pfau‐Kempf, U. Ganse, K. Papadakis, M. Palmroth   +12 more
wiley   +1 more source

Primordial black holes as supermassive black hole seeds

Journal of Cosmology and Astroparticle Physics
Abstract The presence of supermassive black holes (SMBHs, M • ∼ 106-10 M ⊙) in the first cosmic Gyr (z ≳ 6) challenges current models of BH formation and evolution. We propose a novel mechanism for the formation of early SMBH seeds based on primordial black holes (PBHs).
F. Ziparo, S. Gallerani, A. Ferrara
openaire   +2 more sources

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +9 more
wiley   +1 more source

Tiny Galaxies Reveal Secrets of Supermassive Black Holes [PDF]

, 2022
https://www.quantamagazine.org/tiny-galaxies-reveal-secrets-of-supermassive-black-holes-20220314/In 2008, Marta Volonteri helped develop a radical proposal: Astronomers should search the smallest of galaxies for colossal black holes — hulking behemoths ...
Volonteri, Marta
core  

Rotating scalarized supermassive black holes

European Physical Journal C: Particles and Fields
In this study, we investigate rotating black hole solutions within a scalar-Gauss–Bonnet gravity framework that incorporates a squared Gauss–Bonnet term. By employing a quadratic–exponential coupling function between the scalar field and the Gauss–Bonnet
Shoupan Liu, Yunqi Liu, Yan Peng, Cheng-Yong Zhang   +3 more
doaj   +1 more source

Searching for ultra-light bosons and constraining black hole spin distributions with stellar tidal disruption events

Nature Communications, 2022
Stellar tidal disruption events (TDEs) occur when stars pass close enough to supermassive black holes. Here, the authors show that future searches TDEs have potential to uncover the existence of ultralight bosons.
Peizhi Du, Daniel Egaña-Ugrinovic, Rouven Essig, Giacomo Fragione, Rosalba Perna   +4 more
doaj   +1 more source

Asymptotically‐Flat Black Hole Solutions in Symmergent Gravity

Fortschritte der Physik, Volume 72, Issue 4, April 2024.
Abstract Symmergent gravity is an emergent gravity model with an R+R2$R+R^2$ curvature sector and an extended particle sector having new particles beyond the known ones. With constant scalar curvature, asymptotically flat black hole solutions are known to have no sensitivity to the quadratic curvature term (coefficient of R2$R^2$). With variable scalar
Beyhan Puliçe, Reggie C. Pantig, Ali Övgün, Durmuş Demir   +3 more
wiley   +1 more source

Differential rotation in compact objects with hyperons and delta isobars

Astronomische Nachrichten, Volume 345, Issue 2-3, February-March 2024.
Abstract Neutron stars may experience differential rotation on short, dynamical timescales following extreme astrophysical events like binary neutron star mergers. In this work, the masses and radii of differentially rotating neutron star models are computed.
Delaney Farrell, Fridolin Weber, Jia Jie Li, Armen Sedrakian   +3 more
wiley   +1 more source