[PDF] Searches For Gravitational Waves From Binary Black Hole Coalescences With Ground Based Laser Interferometer Across A Wide Parameter Space eBook

Author : Satyanarayan Ray Pitambar Mohapatra
Publisher :
Page : 271 pages
File Size : 22,45 MB
Release : 2012
Category : Black holes (Astronomy)
ISBN :

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This is an exciting time for Gravitational Wave (GW) theory and observations. From a theoretical standpoint, the grand-challenge problem of the full evolution of a Binary Black Hole (BBH) system has been solved numerically, and a variety of source simulations are made available steadfastly. On the observational side, the first generation of state-of-the-art GW detectors, LIGO and Virgo, have achieved their design goal, collected data and provided astrophysically meaningful limits. The second generation of detectors are expected to start running by 2015. Inspired by this zeitgeist, this thesis focuses on the detection of potential GW signatures from the coalescence of BBH in ground-based laser interferometers. The LIGO Scientific Collaboration has implemented different algorithms to search for transient GW signatures, targeting different portions of the BBH coalescence waveform. This thesis has used the existing algorithms to study the detection potential of GW from colliding BBH in LIGO in a wide range of source parameters, such as mass and spin of the black holes, using a sample of data from the last two months of the S5 LIGO science run (14 Aug 2007 to 30 Sept 2007). This thesis also uses numerical relativity waveforms made available via the Numerical INJection Analysis project (NINJA). Methods such as the Chirplet based analysis and the use of multivariate classifiers to optimize burst search algorithms have been introduced in this thesis. These performance studies over a wide parameter space were designed to optimize the discovery potential of ground-based GW detectors and defining strategies for the search of BBH signatures in advanced LIGO data, as a step towards the realization of GW astronomy.

Author : Carl-Johan Haster
Publisher : Springer
Page : 101 pages
File Size : 42,50 MB
Release : 2017-07-27
Category : Science
ISBN : 3319634410

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This thesis presents valuable contributions to several aspects of the rapidly growing field of gravitational wave astrophysics. The potential sources of gravitational waves in globular clusters are analyzed using sophisticated dynamics simulations involving intermediate mass black holes and including, for the first time, high-order post-Newtonian corrections to the equations of motion. The thesis further demonstrates our ability to accurately measure the parameters of the sources involved in intermediate-mass-ratio inspirals of stellar-mass compact objects into hundred-solar-mass black holes. Lastly, it proposes new techniques for the computationally efficient inference on gravitational waves. On 14 September 2015, the LIGO observatory reported the first direct detection of gravitational waves from the merger of a pair of black holes. For a brief fraction of a second, the power emitted by this merger exceeded the combined output of all stars in the visible universe. This has since been followed by another confirmed detection and a third candidate binary black hole merger. These detections heralded the birth of an exciting new field: gravitational-wave astrophysics.

Author :
Publisher :
Page : pages
File Size : 34,27 MB
Release : 2006
Category :
ISBN :

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Gravitational waves, predicted to exist by Einstein's General Theory of Relativity but as yet undetected, are expected to be emitted during violent astrophysical events such as supernovae, black hole interactions and the coalescence of compact binary systems. Their detection and study should lead to a new branch of astronomy. However the experimental challenge is formidable: ground-based detection relies on sensing displacements of order 10^-18 m over a frequency range of tens of hertz to a few kHz. There is currently a large international effort to commission and operate long baseline interferometric detectors including those that comprise LIGO - the Laser Interferometer Gravitational-Wave Observatory - in the USA. In this talk I will give an introduction to the topic of gravitational wave detection and in particular review the status of the LIGO project which is currently taking data at its design sensitivity. I will also look to the future to consider planned improvements in sensitivity for such detectors, focusing on Advanced LIGO, the proposed upgrade to the LIGO project.

Author : Tjonnie G. F. Li
Publisher : Springer
Page : 243 pages
File Size : 45,22 MB
Release : 2015-07-03
Category : Science
ISBN : 3319192736

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Tjonnie Li's thesis covers two applications of Gravitational Wave astronomy: tests of General Relativity in the strong-field regime and cosmological measurements. The first part of the thesis focuses on the so-called TIGER, i.e. Test Infrastructure for General Relativity, an innovative Bayesian framework for performing hypothesis tests of modified gravity using ground-based GW data. After developing the framework, Li simulates a variety of General Relativity deviations and demonstrates the ability of the aforementioned TIGER to measure them. The advantages of the method are nicely shown and compared to other, less generic methods. Given the extraordinary implications that would result from any measured deviation from General Relativity, it is extremely important that a rigorous statistical approach for supporting these results would be in place before the first Gravitational Wave detections begin. In developing TIGER, Tjonnie Li shows a large amount of creativity and originality, and his contribution is an important step in the direction of a possible discovery of a deviation (if any) from General Relativity. In another section, Li's thesis deals with cosmology, describing an exploratory study where the possibility of cosmological parameters measurement through gravitational wave compact binary coalescence signals associated with electromagnetic counterparts is evaluated. In particular, the study explores the capabilities of the future Einstein Telescope observatory. Although of very long term-only applicability, this is again a thorough investigation, nicely put in the context of the current and the future observational cosmology.

Author : Waduthanthree Thilina Dayanga
Publisher :
Page : pages
File Size : 18,53 MB
Release : 2013
Category :
ISBN : 9781303717895

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Estimating GW background play critical role in data analysis. We are still exploring the best way to estimate background of a CBC GW search when one or more signal present in data. In this thesis we try to address this to certain extend through NINJA-2 mock data challenge. However, due to limitations of methods and computer power, for triple coincident GW candidates we only consider loudest two interferometers for background estimation purposes.

Author : Piotr Jaranowski
Publisher : Cambridge University Press
Page : 270 pages
File Size : 14,97 MB
Release : 2009-08-27
Category : Mathematics
ISBN : 0521864593

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Introducing gravitational-wave data analysis, this book is an ideal starting point for researchers entering the field, and researchers currently analyzing data. Detailed derivations of the basic formulae enable readers to apply general statistical concepts to the analysis of gravitational-wave signals. It also discusses new ideas on devising the efficient algorithms.

Author : Joey Shapiro Key
Publisher :
Page : 250 pages
File Size : 48,6 MB
Release : 2010
Category : Astrophysics
ISBN :

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The Laser Interferometer Space Antenna (LISA) and the Laser Interferometer Gravitational-wave Observatory (LIGO) are designed to detect gravitational waves from a wide range of astrophysical sources. The parameter estimation ability of these detectors can be determined by simulating the response to predicted gravitational wave sources with instrument noise and searching for the signals with sophisticated data analysis methods. A possible source of gravitational waves will be beams of radiation from discontinuities on cosmic length strings. Cosmic strings are predicted to form kinks and cusps that travel along the string at close to the speed of light. These disturbances are radiated away as highly beamed gravitational waves that produce a burst-like pulse as the cone of emission sweeps past an observer. The detection of a gravitational wave signal from a cosmic string cusp would illuminate the fields of string theory, cosmology, and relativity. Gravitational wave sources also include coalescing binary systems of compact objects. Colliding galaxies have central black holes that sink to the center of the merged galaxy and begin to orbit one another and emit gravitational waves. Previous LISA data analysis studies have assumed that binary black hole systems have a circular orbit or an extreme mass ratio. It is ultimately necessary to understand the general case of spinning black hole binary systems in eccentric orbits and how LISA observations can be used to measure the eccentricity of the orbits as well as the masses, spins, and luminosity distances of the black holes. Once LISA is operational, the comparison of observations of eccentric and circular black hole binary sources will constrain theories on galaxy mergers in the early universe.

Author : Xingjiang Zhu
Publisher :
Page : pages
File Size : 47,18 MB
Release : 2015
Category :
ISBN :

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The existence of gravitational waves was first predicted by Einstein's general theory of relativity a century ago. However gravitational waves have not yet been directly detected1. Their direct detection will open a new observational window allowing one to listen to the Universe for the first time. Einstein's gravitational spectrum spans from extremely low frequencies, with wave periods comparable to the age of the Universe, to the audio band, with frequencies roughly between 10 Hz and several kilohertz. The subject of this thesis is the direct detection of gravitational waves in two different frequency bands: a) the audio band observed by terrestrial laser interferometers; b) the nanohertz band surveyed by pulsar timing arrays. Ground-based interferometers, such as the Laser Interferometer Gravitational-wave Observatory (LIGO), are primarily searching for signals from binary coalescences of neutron stars and black holes. As the two objects orbit around each other, they lose energy through the emission of gravitational waves. As the orbital period decreases, the gravitational wave frequency and amplitude increase until the binary merges, emitting copious amounts of gravitational waves. Advanced LIGO detectors, which came online in September 2015, are expected to detect tens of such events each year after they reach design sensitivity in around 2019.In addition to those individually detectable events, a gravitational wave background exists as a result of the combined emission of numerous sources throughout the Universe. This provides another promising target for advanced detectors. Modelling such a background signal and predicting its detection prospects is the subject of the first part of this thesis. We present a comprehensive study on the gravitational wave background from compact binary coalescences throughout the Universe. It improves on previous work by using observation-based source distributions and realistic gravitational waveforms. We show that advanced detectors are likely to detect this signal assuming a realistic coalescence rate. We also investigate if subtracting the contribution of individually detectable events can potentially unmask the highly sought primordial signals.Pulsar timing arrays target gravitational waves at the lower nanohertz band. This is achieved through performing long-term radio timing observations of a spatial array of millisecond pulsars. In the second part of this thesis we focus on detection and sky localization of single sources by pulsar timing arrays, in particular signals expected from individual supermassive binary black holes. We have developed two independent coherent methods for this purpose. The first technique is fast and robust, which is adapted from network analysis methods used by ground-based detectors. We demonstrate its effectiveness for three types of sources: circular binaries, eccentric binaries and bursts. To test its robustness, we apply it to realistic synthetic data sets that include effects such as uneven sampling, heterogeneous data spans and measurement precision. With the second technique, we perform an all-sky search for continuous waves in the recent Parkes Pulsar Timing Array data set. Although no statistically significant signals were detected, the quality of the data allows us to set the best limit on the gravitational wave amplitude in the nanohertz regime. With this data set we could detect gravitational waves from supermassive binary black holes with masses higher than one billion solar mass out to a luminosity distance of about 100 Mpc.1Note added - It was announced on 11 February 2016 that a signal from the coalescence of two black holes was detected by two LIGO detectors on 14 September 2015 (Abbott et al. 2016).

Author : David G. Blair
Publisher : Cambridge University Press
Page : 508 pages
File Size : 26,38 MB
Release : 2005-10-13
Category : Science
ISBN : 9780521021029

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This book introduces the concepts of gravitational waves within the context of general relativity. The sources of gravitational radiation for which there is direct observational evidence and those of a more speculative nature are described. He then gives a general introduction to the methods of detection. In the subsequent chapters he has drawn together the leading scientists in the field to give a comprehensive practical and theoretical account of the physics and technology of gravitational wave detection.

Author : Ajit Kembhavi
Publisher : Springer Nature
Page : 181 pages
File Size : 32,76 MB
Release : 2020-08-06
Category : Science
ISBN : 9811557098

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Gravitational waves were first predicted by Albert Einstein in 1916, a year after the development of his new theory of gravitation known as the general theory of relativity. This theory established gravitation as the curvature of space-time produced by matter and energy. To be discernible even to the most sensitive instruments on Earth, the waves have to be produced by immensely massive objects like black holes and neutron stars which are rotating around each other, or in the extreme situations which prevail in the very early ages of the Universe. This book presents the story of the prediction of gravitational waves by Albert Einstein, the early attempts to detect the waves, the development of the LIGO detector, the first detection in 2016, the subsequent detections and their implications. All concepts are described in some detail, without the use of any mathematics and advanced physics which are needed for a full understanding of the subject. The book also contains description of electromagnetism, Einstein’s special theory and general theory of relativity, white dwarfs, neutron stars and black holes and other concepts which are needed for understanding gravitational waves and their effects. Also described are the LIGO detectors and the cutting edge technology that goes into building them, and the extremely accurate measurements that are needed to detect gravitational waves. The book covers these ideas in a simple and lucid fashion which should be accessible to all interested readers. The first detection of gravitational waves was given a lot of space in the print and electronic media. So, the curiosity of the non-technical audience has been aroused about what gravitational waves really are and why they are so important. This book seeks to answer such questions.