We present fully general-relativistic numerical evolutions of self-gravitating tori around spinning black holes with dimensionless spin / = 0.7 parallel or antiparallel to the disk angular momentum. The initial disks are unstable to the hydrodynamic Papaloizou-Pringle instability which causes them to grow persistent orbiting matter clumps. The effect of black hole spin on the growth and saturation of the instability is assessed. We find that the instability behaves similarly to prior simulations with nonspinning black holes, with a shift in frequency due to spin-induced changes in disk orbital period. Copious gravitational waves are generated by these systems, and we analyze their detectability by current and future gravitational wave observatories for a large range of masses. We find that systems of 10 -relevant for black hole-neutron star mergers-are detectable by Cosmic Explorer out to ~300 Mpc, while DECIGO (LISA) will be able to detect systems of 1000 (10 )-relevant for disks forming in collapsing supermassive stars-out to cosmological redshift of ~ 5 ( ~ 1). Computing the accretion rate of these systems we find that these systems may also be promising sources of coincident electromagnetic signals.
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http://dx.doi.org/10.1103/physrevd.103.043013 | DOI Listing |
Magn Reson Imaging
January 2025
Department of Radiology, Semmelweis u. 6, Szeged, Hungary. Electronic address:
Background: In the inflammatory process of multiple sclerosis (MS) several toxic waste products are generated. The clearance of these products might depend on the glymphatic system; however, it's preserved function in MS is uncertain. Recently, it was suggested that this 'waste clearance' system can be examined by measuring the diffusion along the perivascular space (ALPS) index.
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 PDFNat Commun
January 2025
QTF Centre of Excellence, Department of Physics, University of Helsinki, Helsinki, Finland.
The emergence of a local effective theory from a more fundamental theory of quantum gravity with seemingly fewer degrees of freedom is a major puzzle of theoretical physics. A recent approach to this problem is to consider general features of the Hilbert space maps relating these theories. In this work, we construct approximately local observables, or overlapping qubits, from such non-isometric maps.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Physics, University of Trento, Via Sommarive 14, 38123, Povo (TN), Italy.
It has been argued that realistic models of (singularity-free) black holes (BHs) embedded within an expanding Universe are coupled to the large-scale cosmological dynamics, with striking consequences, including pure cosmological growth of BH masses. In this pilot study, we examine the consequences of this growth for the stochastic gravitational wave background (SGWB) produced by inspiraling supermassive cosmologically coupled BHs. We show that the predicted SGWB amplitude is enhanced relative to the standard uncoupled case, while maintaining the [Formula: see text] frequency scaling of the spectral energy density.
View Article and Find Full Text PDFSmall
December 2024
Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, and School of Physics and Optoelectronic, Xiangtan University, Hunan, 411105, P. R. China.
Photocatalysis has garnered significant attention as a sustainable approach for energy conversion and environmental management. 2D black phosphorus (BP) has emerged as a highly promising semiconductor photocatalyst owing to its distinctive properties. However, inherent issues such as rapid recombination of photogenerated electrons and holes severely impede the photocatalytic efficacy of single BP.
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