scholarly journals Probing the nature of black holes: Deep in the mHz gravitational-wave sky

2021 ◽  
Author(s):  
Vishal Baibhav ◽  
Leor Barack ◽  
Emanuele Berti ◽  
Béatrice Bonga ◽  
Richard Brito ◽  
...  
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Wave ◽  
Fundamental Physics ◽  
Black Hole Spacetimes ◽  
Open Questions ◽  
Long Range Interactions ◽  
Gravitational Wave Detectors ◽  
Discovery Potential ◽  
Macroscopic Objects

AbstractBlack holes are unique among astrophysical sources: they are the simplest macroscopic objects in the Universe, and they are extraordinary in terms of their ability to convert energy into electromagnetic and gravitational radiation. Our capacity to probe their nature is limited by the sensitivity of our detectors. The LIGO/Virgo interferometers are the gravitational-wave equivalent of Galileo’s telescope. The first few detections represent the beginning of a long journey of exploration. At the current pace of technological progress, it is reasonable to expect that the gravitational-wave detectors available in the 2035-2050s will be formidable tools to explore these fascinating objects in the cosmos, and space-based detectors with peak sensitivities in the mHz band represent one class of such tools. These detectors have a staggering discovery potential, and they will address fundamental open questions in physics and astronomy. Are astrophysical black holes adequately described by general relativity? Do we have empirical evidence for event horizons? Can black holes provide a glimpse into quantum gravity, or reveal a classical breakdown of Einstein’s gravity? How and when did black holes form, and how do they grow? Are there new long-range interactions or fields in our Universe, potentially related to dark matter and dark energy or a more fundamental description of gravitation? Precision tests of black hole spacetimes with mHz-band gravitational-wave detectors will probe general relativity and fundamental physics in previously inaccessible regimes, and allow us to address some of these fundamental issues in our current understanding of nature.

The stellar graveyard

2019 ◽  
pp. 177-206
Author(s):  
Nils Andersson
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Stellar Evolution ◽  
White Dwarfs ◽  
Supermassive Black Holes ◽  
Compact Objects ◽  
Fermi Gases ◽  
The 1950S

This chapter introduces the different classes of compact objects—white dwarfs, neutron stars, and black holes—that are relevant for gravitational-wave astronomy. The ideas are placed in the context of developing an understanding of the likely endpoint(s) of stellar evolution. Key ideas like Fermi gases and the Chandrasekhar mass are discussed, as is the emergence of general relativity as a cornerstone of astrophysics in the 1950s. Issues associated with different formation channels for, in particular, black holes are considered. The chapter ends with a discussion of the supermassive black holes that are found at the centre of galaxies.

scholarly journals Parameter estimation for heavy binary-black holes with networks of second-generation gravitational-wave detectors

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
Salvatore Vitale ◽  
Ryan Lynch ◽  
Vivien Raymond ◽  
Riccardo Sturani ◽  
John Veitch ◽  
...  
Keyword(s):  
Black Holes ◽  
Parameter Estimation ◽  
Gravitational Wave ◽  
Second Generation ◽  
Binary Black Holes ◽  
Gravitational Wave Detectors

scholarly journals Terrestrial gravity fluctuations

2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Jan Harms
Keyword(s):  
Gravitational Wave ◽  
Early Warning Systems ◽  
Mitigation Strategies ◽  
Noise Mitigation ◽  
Fundamental Physics ◽  
Terrestrial Gravity ◽  
Gravitational Wave Detectors ◽  
Density Perturbations ◽  
New Generation ◽  
Physics Experiments

Abstract Terrestrial gravity fluctuations are a target of scientific studies in a variety of fields within geophysics and fundamental-physics experiments involving gravity such as the observation of gravitational waves. In geophysics, these fluctuations are typically considered as signal that carries information about processes such as fault ruptures and atmospheric density perturbations. In fundamental-physics experiments, it appears as environmental noise, which needs to be avoided or mitigated. This article reviews the current state-of-the-art of modeling high-frequency terrestrial gravity fluctuations and of gravity-noise mitigation strategies. It hereby focuses on frequencies above about 50 mHz, which allows us to simplify models of atmospheric gravity perturbations (beyond Brunt–Väisälä regime) and it guarantees as well that gravitational forces on elastic media can be treated as perturbation. Extensive studies have been carried out over the past two decades to model contributions from seismic and atmospheric fields especially by the gravitational-wave community. While terrestrial gravity fluctuations above 50 mHz have not been observed conclusively yet, sensitivity of instruments for geophysical observations and of gravitational-wave detectors is improving, and we can expect first observations in the coming years. The next challenges include the design of gravity-noise mitigation systems to be implemented in current gravitational-wave detectors, and further improvement of models for future gravitational-wave detectors where terrestrial gravity noise will play a more important role. Also, many aspects of the recent proposition to use a new generation of gravity sensors to improve real-time earthquake early-warning systems still require detailed analyses.

GRAVITATIONAL WAVEFORMS FOR BINARY BLACK HOLES

2011 ◽  
Vol 20 (10) ◽  
pp. 2081-2086
Author(s):  
BALA R IYER
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Numerical Relativity ◽  
Current Status ◽  
Next Generation ◽  
Binary Black Holes ◽  
Gravitational Wave Detectors ◽  
Body Method

Over the last decade gravitational waveforms of binary black holes have been investigated using a variety of approaches like the Multipolar post-Minkowskian formalism, Numerical Relativity and the Effective-One-Body method. We review these complementary approaches and summarize the current status of these investigations of relevance to construct the best templates for the next generation Advanced gravitational wave detectors.

scholarly journals Testing general relativity using gravitational wave signals from the inspiral, merger and ringdown of binary black holes

2017 ◽  
Vol 35 (1) ◽  
pp. 014002 ◽  
Author(s):  
Abhirup Ghosh ◽  
Nathan K Johnson-McDaniel ◽  
Archisman Ghosh ◽  
Chandra Kant Mishra ◽  
Parameswaran Ajith ◽  
...  
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Wave ◽  
Binary Black Holes

scholarly journals Parameterized and Consistency Tests of Gravity with GravitationalWaves: Current and Future

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 5 ◽  
Author(s):  
Zack Carson ◽  
Kent Yagi
Keyword(s):  
General Relativity ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Dynamical Regime ◽  
Future Prospects ◽  
Tests Of General Relativity ◽  
Open Questions ◽  
Tests Of Gravity ◽  
Multi Band

Gravitational wave observations offer unique opportunities to probe gravity in the strong and dynamical regime, which was difficult to access previously. We here review two theory-agnostic ways to carry out tests of general relativity with gravitational waves, namely (i) parameterized waveform tests and (ii) consistency tests between the inspiral and merger-ringdown portions. For each method, we explain the formalism, followed by results from existing events, and finally we discuss future prospects with upgraded detectors, including the possibility of using multi-band gravitational-wave observations with ground-based and space-borne interferometers. We show that such future observations have the potential to improve upon current bounds on theories beyond general relativity by many orders of magnitude. We conclude by listing several open questions that remain to be addressed.

The laser gravitational compass: A spheroidal interferometric gravitational observatory

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040020
Author(s):  
Ivan S. Ferreira ◽  
C. Frajuca ◽  
Nadja S. Magalhaes ◽  
M. D. Maia ◽  
Claudio M. G. Sousa
Keyword(s):  
General Relativity ◽  
Gravitational Field ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Gravitational Wave Detectors ◽  
Alternative Theories ◽  
Theories Of Gravitation

Using the observational properties of Einstein’s gravitational field it is shown that a minimum of four non-coplanar mass probes are necessary for a Michelson and Morley interferometer to detect gravitational waves within the context of General Relativity. With fewer probes, some alternative theories of gravitation can also explain the observations. The conversion of the existing gravitational wave detectors to four probes is also suggested.

scholarly journals Quasi-normal modes of static spherically symmetric black holes in f(R) theory

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Sayak Datta ◽  
Sukanta Bose
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Black Hole ◽  
Gravitational Wave ◽  
Normal Modes ◽  
Einstein Frame ◽  
Spherically Symmetric ◽  
Inhomogeneous Term ◽  
Binary Black Hole ◽  
Special Case

AbstractWe study the quasi-normal modes (QNMs) of static, spherically symmetric black holes in f(R) theories. We show how these modes in theories with non-trivial f(R) are fundamentally different from those in general relativity. In the special case of $$f(R) = \alpha R^2$$f(R)=αR2 theories, it has been recently argued that iso-spectrality between scalar and vector modes breaks down. Here, we show that such a break down is quite general across all f(R) theories, as long as they satisfy $$f''(0)/(1+f''(0)) \ne 0$$f′′(0)/(1+f′′(0))≠0, where a prime denotes derivative of the function with respect to its argument. We specifically discuss the origin of the breaking of isospectrality. We also show that along with this breaking the QNMs receive a correction that arises when $$f''(0)/(1+f'(0)) \ne 0$$f′′(0)/(1+f′(0))≠0 owing to the inhomogeneous term that it introduces in the mode equation. We discuss how these differences affect the “ringdown” phase of binary black hole mergers and the possibility of constraining f(R) models with gravitational-wave observations. We also find that even though the iso-spectrality is broken in f(R) theories, in general, nevertheless in the corresponding scalar-tensor theories in the Einstein frame it is unbroken.

scholarly journals Probing seed black holes using future gravitational-wave detectors

2009 ◽  
Vol 26 (20) ◽  
pp. 204009 ◽  
Author(s):  
Jonathan R Gair ◽  
Ilya Mandel ◽  
Alberto Sesana ◽  
Alberto Vecchio
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Gravitational Wave Detectors
Sign in / Sign up

Export Citation Format

Share Document