Tidal deformation of quantum black holes

Author(s):  
Ram Brustein ◽  
Yotam Sherf

The response of a gravitating object to an external tidal field is encoded in its Love numbers, which identically vanish for classical black holes (BHs). Here we show, using standard time-independent quantum perturbation theory, that for a quantum BH, generically, the Love numbers are nonvanishing and negative. We calculate the quadrupolar electric quantum Love number of slowly rotating BHs and show that it depends most strongly on the first excited level of the quantum BH. Finally, we discuss the detectability of the quadrupolar quantum Love number in future precision gravitational-wave observations and show that, under favourable circumstances, its magnitude is large enough to imprint an observable signature on the gravitational waves emitted during the inspiral. Phase of two moderately spinning BHs.

2021 ◽  
Author(s):  
Blenda Úlima Rodrigues Cesar Guedes ◽  
Antonio de Pádua Santos ◽  
Tiago Alessandro Espínola Ferreira

Gravitational waves were predicted by Albert Einstein more than a century ago, but only in 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) was able to detect them. The gravitational wave phenomenon can be compared to spreading water from a lake after a stone has been thrown into it. Here, gravitational wave generation comes from an astronomical binary system formed by black holes or neutron stars. However, unlike the water, the amplitude of those gravitational waves is on a scale smaller than a proton’s size. Despite this, we can describe it with simple equations in a phenomenological way. We can model those waves on a regular computer using post Newtonian physics. Here we were able to generate gravitational waves from computational simulations and make its data analyze. When a gravitational wave is detected in the real-world problem, there is a great interest in establishing the physical features of the astronomical bodies involved in the process. In this way, we propose applying a simple neural network to receive the gravitational wave data and infer information about the astronomical bodies’ mass. The experimental results show that a simple neural network can extract mass information from the gravitational wave data. The recognition process proposed is much more straightforward than the complex computation based on numerical relativity for gravitational wave data analysis.


2011 ◽  
Vol 03 ◽  
pp. 408-416
Author(s):  
H. P. DE OLIVEIRA ◽  
E. L. RODRIGUES

We analyze the non-frontal collisions of two Schwarzschild black holes in the realm of general Robinson-Trautman spacetimes using a numerical code based on spectral methods. In this process, two black holes collide and form a single black hole while a certain amount of the initial mass is carried away by gravitational waves. We determined the forms of the gravitational waves and the efficiency of this process for frontal and non-frontal collisions. We found numerical evidence that the distribution of mass qloss can be described by a function typically used in nonextensive statistics.


2016 ◽  
Vol 31 (4) ◽  
pp. 464-492 ◽  
Author(s):  
Stefan Helmreich

In February 2016, U.S.-based astronomers announced that they had detected gravitational waves, vibrations in the substance of space-time. When they made the detection public, they translated the signal into sound, a “chirp,” a sound wave swooping up in frequency, indexing, scientists said, the collision of two black holes 1.3 billion years ago. Drawing on interviews with gravitational-wave scientists at MIT and interpreting popular representations of this cosmic audio, I ask after these scientists’ acoustemology—that is, what the anthropologist of sound Steven Feld would call their “sonic way of knowing and being.” Some scientists suggest that interpreting gravitational-wave sounds requires them to develop a “vocabulary,” a trained judgment about how to listen to the impress of interstellar vibration on the medium of the detector. Gravitational-wave detection sounds, I argue, are thus articulations of theories with models and of models with instrumental captures of the cosmically nonhuman. Such articulations, based on mathematical and technological formalisms—Einstein’s equations, interferometric observatories, and sound files—operate alongside less fully disciplined collections of acoustic, auditory, and even musical metaphors, which I call informalisms. Those informalisms then bounce back on the original articulations, leading to rhetorical reverb, in which articulations—amplified through analogies, similes, and metaphors—become difficult to fully isolate from the rhetorical reflections they generate. Filtering analysis through a number of accompanying sound files, this article contributes to the anthropology of listening, positing that scientific audition often operates by listening through technologies that have been tuned to render theories and their accompanying formalisms both materially explicit and interpretively resonant.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Chan Park ◽  
Dong-Hoon Kim

AbstractWe provide analysis to determine the effects of gravitational waves on electromagnetic waves, using perturbation theory in general relativity. Our analysis is performed in a completely covariant manner without invoking any coordinates. For a given observer, using the geometrical-optics approach, we work out the perturbations of the phase, amplitude, frequency and polarization properties–axes of ellipse and ellipticity of light, due to gravitational waves. With regard to the observation of gravitational waves, we discuss the measurement of Stokes parameters, through which the antenna patterns are presented to show the detectability of the gravitational wave signals.


Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 43 ◽  
Author(s):  
Jahed Abedi ◽  
Niayesh Afshordi ◽  
Naritaka Oshita ◽  
Qingwen Wang

Black Holes are possibly the most enigmatic objects in our universe. From their detection in gravitational waves upon their mergers, to their snapshot eating at the centres of galaxies, black hole astrophysics has undergone an observational renaissance in the past four years. Nevertheless, they remain active playgrounds for strong gravity and quantum effects, where novel aspects of the elusive theory of quantum gravity may be hard at work. In this review article, we provide an overview of the strong motivations for why “Quantum Black Holes” may be radically different from their classical counterparts in Einstein’s General Relativity. We then discuss the observational signatures of quantum black holes, focusing on gravitational wave echoes as smoking guns for quantum horizons (or exotic compact objects), which have led to significant recent excitement and activity. We review the theoretical underpinning of gravitational wave echoes and critically examine the seemingly contradictory observational claims regarding their (non-)existence. Finally, we discuss the future theoretical and observational landscape for unraveling the “Quantum Black Holes in the Sky”.


Author(s):  
Marliana Marliana ◽  
Agustina Widiyani ◽  
Azwar Sutiono ◽  
Agus Suroso ◽  
Freddy P. Zen

<p class="AbstractEnglish"><strong>Abstract:</strong> The direct detection of gravitational waves from binary black holes and neutron stars have been taking a new oportunities to test teori of gravity.The gravitational wave is affected by the modification of a gravity theory during propagation at cosmological distances. By comparing general equation of gravtiational wave and modification of gravity theory, is obtained equation of gravitational wave for the generalized Proca theories. As a result, we find equation of gravitational wave for the generalized Proca theory. We conclude that the massive vector field affected propagation of gravitational wave.  we can use the result to test the generalized Proca theory.    </p><p class="AbstrakIndonesia"><strong>Abstrak:</strong> Dengan terdeteksinya gelombang gravitasi secara langsung dari biner lubang hitam dan bintang neutron menjadi kesempatan untuk dapat menguji teori gravitasi yang sedang dikembangkan.Gelombang gravitasi secara umum dipengaruhi oleh modifikasi teori gravitasi selama penjalarannya pada jarak kosmologi. Dengan membandingkan persamaan gelombang gravitasi dengan teori modifikasi yang dikembangkan, diperoleh persamaan umum gelombang gravitasi dari teori gravitasi yang dikembangkan. Pada artikel ini diperoleh persamaan gelombang gravitasi untuk teori Proca yang digeneralisasi. Dapat disimpulkan bahwa fungsi yang mengandung vektor medan masif dapat mempengaruhi gelombang gravitasi. Persamaan ini dapat digunakan untuk menguji teori Proca yang digeneralisasi.</p>


2019 ◽  
Vol 7 ◽  
Author(s):  
Joey Shapiro Key ◽  
LIGO Scientific Collaboration

On a summer day in 2017, astronomers around the world received a message about an exciting collision of two stars far, far away. The message was sent by a team of astronomers from the LIGO and Virgo observatories. These new observatories are very different from the telescopes we have used to study our Universe up until now. LIGO and Virgo are gravitational wave observatories, listening for quiet ripples in spacetime created by the collisions of distant black holes and neutron stars. On August 17, 2017 LIGO and Virgo detected a signal that astronomers named GW170817, from the collision of two neutron stars. Less than two seconds later, NASA's Fermi satellite caught a signal, known as a gamma-ray burst, and within minutes, telescopes around the world began searching the sky. Telescopes in South America found the location of the collision in a distant galaxy known as NGC 4993. For the weeks and months that followed, astronomers watched the galaxy and the fading light from the collision. This is a new kind of multi-messenger astronomy where, for the first time, the same event was observed by both gravitational waves and light.


Author(s):  
Rabinarayan Swain ◽  
Priyasmita Panda ◽  
Hena Priti Lima ◽  
Bijayalaxmi Kuanar ◽  
Biswajit Dalai

Detection of Gravitational waves opened a new path for cosmological study in a new approach. From the detection of gravitational waves signal by advanced LIGO, its research climbed the peak. After the collaboration of LIGO and Virgo, several observations get collected from different sources of binary systems like black holes, binary neutron stars even both binary black hole and neutron star. The rigorous detection of gravitational signals may provide an additional thrust in the study of complex binary systems, dark matter, dark energy, Hubble constant, etc. In this review paper, we went through multiple research manuscripts to analyze gravitational wave signals. Here we have reviewed the history and current situation of gravitational waves detection, and we explained the concept and process of detection. Also, we go through different parts of a detector and their working. Then multiple gravitational wave signals are focused, originated from various sources and then found correlation between them. From this, the contribution of gravitational waves in different fields like complex binary systems (black holes, neutron stars), dark matter, dark energy and Hubble Constant have been discussed in this manuscript.


Author(s):  
John W. Moffat

The author visits one of the two Laser Interferometer Gravitational- Wave Observatory (LIGO) sites in the United States, at Hanford, Washington. This is where scientists are detecting gravitational waves generated by faraway merging black holes and neutron stars. He meets the people who work there and has discussions with some of them. The director gives him a tour of the LIGO experimental installation, describing the work, the technological details of the apparatus, and answers his questions. On the final day of the visit, the author gives a talk to the LIGO group on gravitational waves and on an alternative gravitational theory.


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