The electromagnetic bremsstrahlung spectrum for the dipole which falling by a spiral orbit into the Schwarzschild black hole was found. The characteristic features in this electromagnetic spectrum can be used for determine of the black hole mass by the new way. This new way (if implemented) provides higher accuracy in determining of the black hole mass. Also these features in the spectrum can be used for determine of the certain characteristics in the black hole magnetosphere or in the accretion disk characteristics around the black hole. It is also shown that the asymptotic behavior of this spectrum (at high frequencies) is practically independent from the impact parameter of the falling dipole.
The free fall of electric charges and dipoles, radial and freely falling into the Schwarzschild black hole event horizon, was considered. Inverse effect of electromagnetic fields on the black hole is neglected. Dipole was considered as a point particle, so the deformation associated with exposure by tidal forces are neglected. According to the theorem, the lack of hair of black holes, multipole magnetic fields must be fully emitted by multipole fall into a black hole. The spectrum of electromagnetic radiation power for these multipoles (monopole and dipole) was found. Differences were found in the spectra for different orientations of the falling dipole. A general method has been developed to find radiated electromagnetic multipole fields for the free falling multipoles into a black hole (including higher order multipoles - quadrupoles, etc.). The electromagnetic spectrum can be compared with observational data from stellar mass and smaller black holes.
We propose an analogy between the quantum physics of a black hole in its late stages of the evaporation process and a superfluid Bose Einstein Condensate (BEC), based on the Horowitz and Maldacena quantum final state projection model [JHEP 2004(02), 008]. The superfluid region is considered to be analogous to the interior of a black hole, and the normal fluid/superfluid interface is compared to the event horizon of a black hole. We theoretically investigate the possibility of recovering the wavefunction of particles incident on a superfluid BEC from the normal fluid, facilitated by the mode conversion processes occurring at the normal fluid/superfluid BEC interface. We also study how the correlations of an infalling mode with an external memory system can be preserved in the process, similar to Hayden and Preskills information mirror model for a black hole [JHEP 2007(09), 120]. Based on these analogies, we conjecture that the quantum state of bosons entering a black hole in its final state is the superfluid quantum ground state of interacting bosons. Our analogy suggests that the wavefunction of bosons falling into a black hole can be recovered from the outgoing Hawking modes. In the particular case when a hole-like quasiparticle (a density dip) is incident on the superfluid BEC causing the superfluid to shrink in size, our model indicates that the evaporation is unitary.
The spin modulated gravitational wave signals, which we shall call smirches, emitted by stellar mass black holes tumbling and inspiralling into massive black holes have extremely complicated shapes. Tracking these signals with the aid of pattern matching techniques, such as Wiener filtering, is likely to be computationally an impossible exercise. In this article we propose using a mixture of optimal and non-optimal methods to create a search hierarchy to ease the computational burden. Furthermore, by employing the method of principal components (also known as singular value decomposition) we explicitly demonstrate that the effective dimensionality of the search parameter space of smirches is likely to be just three or four, much smaller than what has hitherto been thought to be about nine or ten. This result, based on a limited study of the parameter space, should be confirmed by a more exhaustive study over the parameter space as well as Monte-Carlo simulations to test the predictions made in this paper.
When two black holes merge, the late stage of gravitational wave emission is a superposition of exponentially damped sinusoids. According to the black hole no-hair theorem, this ringdown spectrum depends only on the mass and angular momentum of the final black hole. An observation of more than one ringdown mode can test this fundamental prediction of general relativity. Here we provide strong observational evidence for a multimode black hole ringdown spectrum using the gravitational wave event GW190521, with a Bayes factor of $sim 40$ preferring two fundamental modes over one. The dominant mode is the $ell=m=2$ harmonic, and the sub-dominant mode corresponds to the $ell=m=3$ harmonic. We estimate the redshifted mass and dimensionless spin of the final black hole as $330^{+30}_{-40},mathrm{M}_odot$ and $0.87^{+0.05}_{-0.10}$, respectively. The detection of the two modes disfavors a binary progenitor with equal masses; the mass ratio is constrained to $0.4^{+0.2}_{-0.3}$. We find that the final black hole is consistent with the no hair theorem and constrain the fractional deviation from general relativity of the sub-dominant modes frequency to be $-0.01^{+0.07}_{-0.11}$.
An atom falling freely into a Kerr black hole in a Boulware-like vacuum is shown to emit radiation with a Planck spectrum at the Hawking temperature. For a cloud of falling atoms with random initial times, the radiation is thermal. The existence of this radiation is due to the acceleration of the vacuum field modes with respect to the falling atom. Its properties can be traced to the dominant role of conformal quantum mechanics (CQM) in the neighborhood of the event horizon. We display this effect for a scalar field, though the acceleration radiation has a universal conformal behavior that is exhibited by all fields in the background of generic black holes.
Alexander Shatskiy
,I.D. Novikov
,Alexandr Malinovsky
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(2014)
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"Spectrum for the electric dipole which nonradially falling into a black hole"
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Alexander Shatskiy Doctor
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