scholarly journals Gravitational Waves from Mirror World

Physics ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 67-75
Author(s):  
Revaz Beradze ◽  
Merab Gogberashvili
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Star Formation ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Binary Systems ◽  
Laser Interferometer ◽  
Matter Density ◽  
Mirror Matter

In this paper we consider the properties of the 10 confirmed by the LIGO (Laser Interferometer Gravitational-Wave Observatory) Collaboration gravitational wave signals from the black hole mergers. We want to explain non-observation of electromagnetic counterpart and higher then expected merging rates of these events, assuming the existence of their sources in the hidden mirror universe. Mirror matter, which interacts with our world only through gravity, is a candidate of dark matter and its density can exceed ordinary matter density five times. Since mirror world is considered to be colder, star formation there started earlier and mirror black holes had more time to pick up the mass and to create more binary systems within the LIGO reachable zone. In total, we estimate factor of 15 amplification of black holes merging rate in mirror world with respect to our world, which is consistent with the LIGO observations.

scholarly journals Gravitational waves: A review on the future astronomy

2022 ◽  
pp. 38-50
Author(s):  
Rabinarayan Swain ◽  
Priyasmita Panda ◽  
Hena Priti Lima ◽  
Bijayalaxmi Kuanar ◽  
Biswajit Dalai
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Dark Energy ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Binary Systems ◽  
Hubble Constant ◽  
New Approach ◽  
Different Sources

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.

The Shadow of the Black Hole

2020 ◽  
Author(s):  
John W. Moffat
Keyword(s):  
United States ◽  
Black Holes ◽  
Black Hole ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Laser Interferometer ◽  
The United States ◽  
Gravitational Theory ◽  
The People

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.

scholarly journals Recoiling black holes in static and evolving dark matter halo potential

2015 ◽  
pp. 17-28 ◽  
Author(s):  
M. Smole
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Critical Velocity ◽  
Complete Removal ◽  
Matter Density ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Critical Amplitude ◽  
Density Distributions

We follow trajectories of kicked black holes in static and evolving dark matter halo potential. We explore both NFW and Einasto dark matter density distributions. Considered dark matter halos represent hosts of massive spiral and elliptical field galaxies. We study critical amplitude of kick velocity necessary for complete black hole ejection at various redshifts and find that ~40% lower kick velocities can remove black holes from their host haloes at z = 7 compared to z = 1. The greatest difference between static and evolving potential occurs near the critical velocity for black hole ejection and at high redshifts. When NFW and Einasto density distributions are compared ~30% higher kick velocities are needed for complete removal of BHs from dark matter halo described by NFW profile.

scholarly journals BLACK HOLES COLLISION IN GENERAL ROBINSON-TRAUTMAN SPACETIMES: WAVE FORMS AND THE EFFICIENCY OF THE GRAVITATIONAL WAVE EXTRACTION

2011 ◽  
Vol 03 ◽  
pp. 408-416
Author(s):  
H. P. DE OLIVEIRA ◽  
E. L. RODRIGUES
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Spectral Methods ◽  
Numerical Code ◽  
Numerical Evidence ◽  
Nonextensive Statistics ◽  
Wave Forms ◽  
Frontal Collisions

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.

scholarly journals Observational Constraints on Black Hole Spin

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Christopher S. Reynolds
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Wave ◽  
Binary Systems ◽  
Annual Review ◽  
Formation Mechanisms ◽  
Publication Date ◽  
X Ray ◽  
Spin Effects ◽  
Black Hole Spin

The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Furthermore, spin can be a potent energy source for powering relativistic jets and energetic particle acceleration. In this review, I describe the techniques currently used to detect and measure the spins of black holes. It is shown that: ▪ Two well-understood techniques, X-ray reflection spectroscopy and thermal continuum fitting, can be used to measure the spins of black holes that are accreting at moderate rates. There is a rich set of other electromagnetic techniques allowing us to extend spin measurements to lower accretion rates. ▪ Many accreting supermassive black holes are found to be rapidly spinning, although a population of more slowly spinning black holes emerges at masses above M > 3 × 107 M⊙ expected from recent structure formation models. ▪ Many accreting stellar-mass black holes in X-ray binary systems are rapidly spinning and must have been born in this state. ▪ The advent of gravitational wave astronomy has enabled the detection of spin effects in merging binary black holes. Most of the premerger black holes are found to be slowly spinning, a notable exception being an object that may itself be a merger product. ▪ The stark difference in spins between the black hole X-ray binary and the binary black hole populations shows that there is a diversity of formation mechanisms. Given the array of new electromagnetic and gravitational wave capabilities currently being planned, the future of black hole spin studies is bright. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Primordial Black Holes as Dark Matter: Recent Developments

2020 ◽  
Vol 70 (1) ◽  
pp. 355-394 ◽  
Author(s):  
Bernard Carr ◽  
Florian Kühnel
Keyword(s):  
Elementary Particle ◽  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Galactic Nuclei ◽  
Matter Density ◽  
Primordial Black Holes ◽  
Poisson Effect ◽  
Recent Developments

Although the dark matter is usually assumed to be made up of some form of elementary particle, primordial black holes (PBHs) could also provide some of it. However, various constraints restrict the possible mass windows to 1016–1017 g, 1020–1024 g, and 10–103 M⊙. The last possibility is contentious but of special interest in view of the recent detection of black hole mergers by LIGO/Virgo. PBHs might have important consequences and resolve various cosmological conundra even if they account for only a small fraction of the dark matter density. In particular, those larger than 103 M⊙ could generate cosmological structures through the seed or Poisson effect, thereby alleviating some problems associated with the standard cold dark matter scenario, and sufficiently large PBHs might provide seeds for the supermassive black holes in galactic nuclei. More exotically, the Planck-mass relics of PBH evaporations or stupendously large black holes bigger than 1012 M⊙ could provide an interesting dark component.

scholarly journals A Study on the Detection Method of Dark Matter using Gravitational Waves

2021 ◽  
Vol 2083 (2) ◽  
pp. 022044
Author(s):  
Zheng Li ◽  
Chenyu Yang ◽  
Xinen Zhou
Keyword(s):  
Dark Matter ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Laser Interferometer ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Detection Schemes ◽  
The Universe ◽  
Matter Detection ◽  
Shed Light

Abstract Dark matter is a type of invisible matter that analytically exists in the universe. Nowadays, scholars have yet detected it and confirmed its presence experimentally. Einstein predicted gravitational waves based on his general theory of relativity. In 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) first detected the gravitational wave. This paper reviews the background of dark matter and gravitational waves and introduces the method of detecting dark matter with gravitational waves. Moreover, the feasibility of the scenario has been verified based on information retrieval and theoretical analysis. These results shed light on the future detection schemes of dark matter detection.

scholarly journals A Dynamical Gravitational Wave Source in a Dense Cluster

2016 ◽  
Vol 33 ◽  
Author(s):  
Jarrod R. Hurley ◽  
Anna C. Sippel ◽  
Christopher A. Tout ◽  
Sverre J. Aarseth
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Wave ◽  
Globular Clusters ◽  
Binary Systems ◽  
Star Cluster ◽  
High Density ◽  
Wave Source ◽  
Black Hole Binaries ◽  
Dense Cluster

AbstractMaking use of a new N-body model to describe the evolution of a moderate-size globular cluster, we investigate the characteristics of the population of black holes within such a cluster. This model reaches core-collapse and achieves a peak central density typical of the dense globular clusters of the Milky Way. Within this high-density environment, we see direct confirmation of the merging of two stellar remnant black holes in a dynamically formed binary, a gravitational wave source. We describe how the formation, evolution, and ultimate ejection/destruction of binary systems containing black holes impacts the evolution of the cluster core. Also, through comparison with previous models of lower density, we show that the period distribution of black hole binaries formed through dynamical interactions in this high-density model favours the production of gravitational wave sources. We confirm that the number of black holes remaining in a star cluster at late times and the characteristics of the binary black hole population depend on the nature of the star cluster, critically on the number density of stars and by extension the relaxation timescale.

scholarly journals Coalescence of Kerr Black Holes—Binary Systems from GW150914 to GW170814

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1017
Author(s):  
Bogeun Gwak
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Gravitational Wave ◽  
Orbital Angular Momentum ◽  
Binary Systems ◽  
Analytical Form ◽  
Angular Momenta ◽  
Binary Black Hole ◽  
Kerr Black Holes

We investigate the energy of the gravitational wave from a binary black hole merger by the coalescence of two Kerr black holes with an orbital angular momentum. The coalescence is constructed to be consistent with particle absorption in the limit in which the primary black hole is sufficiently large compared with the secondary black hole. In this limit, we analytically obtain an effective gravitational spin–orbit interaction dependent on the alignments of the angular momenta. Then, binary systems with various parameters including equal masses are numerically analyzed. According to the numerical analysis, the energy of the gravitational wave still depends on the effective interactions, as expected from the analytical form. In particular, we ensure that the final black hole obtains a large portion of its spin angular momentum from the orbital angular momentum of the initial binary black hole. To estimate the angular momentum released by the gravitational wave in the actual binary black hole, we apply our results to observations at the Laser Interferometer Gravitational-Wave Observatory: GW150914, GW151226, GW170104, GW170608 and GW170814.

scholarly journals Quantum Black Holes in the Sky

Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 43 ◽  
Author(s):  
Jahed Abedi ◽  
Niayesh Afshordi ◽  
Naritaka Oshita ◽  
Qingwen Wang
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Review Article ◽  
Compact Objects ◽  
Theoretical Underpinning ◽  
The Past ◽  
Einstein’S General Relativity

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”.

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