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Abraham Loeb - One of the best experts on this subject based on the ideXlab platform.
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constraining relativistic generalizations of modified newtonian dynamics with Gravitational Waves
Physical Review Letters, 2017Co-Authors: Paul M. Chesler, Abraham LoebAbstract:In the weak-field limit of general relativity, Gravitational Waves obey linear equations and propagate at the speed of light. These properties of general relativity are supported by the observation of ultrahigh-energy cosmic rays as well as by LIGO's recent detection of gravitation Waves. We argue that two existing relativistic generalizations of modified Newtonian dynamics, namely, the generalized Einstein-aether theory and bimetric modified Newtonian dynamics, display fatal inconsistencies with these observations.
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Constraining Relativistic Generalizations of Modified Newtonian Dynamics with Gravitational Waves
Physical Review Letters, 2017Co-Authors: Paul M. Chesler, Abraham LoebAbstract:In the weak-field limit of General Relativity, Gravitational Waves obey linear equations and propagate at the speed of light. These properties of General Relativity are supported by the observation of ultra high energy cosmic rays as well as by LIGO's recent detection of gravitation Waves. We argue that two existing relativistic generalizations of Modified Newtonian Dynamics, namely Generalized Einstein-Aether theory and BIMOND, display fatal inconsistencies with these observations.
Paul M. Chesler - One of the best experts on this subject based on the ideXlab platform.
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constraining relativistic generalizations of modified newtonian dynamics with Gravitational Waves
Physical Review Letters, 2017Co-Authors: Paul M. Chesler, Abraham LoebAbstract:In the weak-field limit of general relativity, Gravitational Waves obey linear equations and propagate at the speed of light. These properties of general relativity are supported by the observation of ultrahigh-energy cosmic rays as well as by LIGO's recent detection of gravitation Waves. We argue that two existing relativistic generalizations of modified Newtonian dynamics, namely, the generalized Einstein-aether theory and bimetric modified Newtonian dynamics, display fatal inconsistencies with these observations.
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Constraining Relativistic Generalizations of Modified Newtonian Dynamics with Gravitational Waves
Physical Review Letters, 2017Co-Authors: Paul M. Chesler, Abraham LoebAbstract:In the weak-field limit of General Relativity, Gravitational Waves obey linear equations and propagate at the speed of light. These properties of General Relativity are supported by the observation of ultra high energy cosmic rays as well as by LIGO's recent detection of gravitation Waves. We argue that two existing relativistic generalizations of Modified Newtonian Dynamics, namely Generalized Einstein-Aether theory and BIMOND, display fatal inconsistencies with these observations.
B P Abbott - One of the best experts on this subject based on the ideXlab platform.
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first search for nontensorial Gravitational Waves from known pulsars
Physical Review Letters, 2018Co-Authors: B P Abbott, R Abbott, T D Abbott, M R Abernathy, K Ackley, C Adams, P Addesso, R X Adhikari, V B Adya, C AffeldtAbstract:We present results from the first directed search for nontensorial Gravitational Waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict Waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of Gravitational Waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.
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observation of Gravitational Waves from a binary black hole merger
Physical Review Letters, 2016Co-Authors: B P Abbott, F Acernese, R Abbott, T D Abbott, M R Abernathy, K Ackley, C Adams, P Addesso, T Adams, R AdhikariAbstract:On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient Gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak Gravitational-wave strain of $1.0 \times 10^{-21}$. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1 {\sigma}. The source lies at a luminosity distance of $410^{+160}_{-180}$ Mpc corresponding to a redshift $z = 0.09^{+0.03}_{-0.04}$. In the source frame, the initial black hole masses are $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$, and the final black hole mass is $62^{+4}_{-4} M_\odot$, with $3.0^{+0.5}_{-0.5} M_\odot c^2$ radiated in Gravitational Waves. All uncertainties define 90% credible intervals.These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of Gravitational Waves and the first observation of a binary black hole merger.
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observation of Gravitational Waves from a binary black hole merger
Vasconcellos C.A.Z. (ed.) Centennial of General Relativity: A Celebration, 2016Co-Authors: B P Abbott, F Acernese, R Abbott, T D Abbott, K Ackley, C Adams, P Addesso, T Adams, M Abernathy, R X AdhikariAbstract:On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient Gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak Gravitational-wave strain of 1.0×10^(−21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410 +160/−180 Mpc corresponding to a redshift z=0.09 +0.03/−0.04. In the source frame, the initial black hole masses are 36+5−4M_⊙ and 29+4−4M_⊙, and the final black hole mass is 62+4−4M⊙, with 3.0+0.5−0.5M_⊙c^2 radiated in Gravitational Waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of Gravitational Waves and the first observation of a binary black hole merger.
Tomohiro Fujita - One of the best experts on this subject based on the ideXlab platform.
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primordial Gravitational Waves from axion gauge fields dynamics
Journal of Cosmology and Astroparticle Physics, 2017Co-Authors: Emanuela Dimastrogiovanni, Matteo Fasiello, Tomohiro FujitaAbstract:Inspired by the chromo-natural inflation model of Adshead&Wyman, we reshape its scalar content to relax the tension with current observational bounds. Besides an inflaton, the setup includes a spectator sector in which an axion and SU(2) gauge fields are coupled via a Chern-Simons-type term. The result is a viable theory endowed with an alternative production mechanism for Gravitational Waves during inflation. The Gravitational wave signal sourced by the spectator fields can be much larger than the contribution from standard vacuum fluctuations, it is distinguishable from the latter on the basis of its chirality and, depending on the theory parameters values, also its tilt. This production process breaks the well-known relation between the tensor-to-scalar ratio and the energy scale of inflation. As a result, even if the Hubble rate is itself too small for the vacuum to generate a tensor amplitude detectable by upcoming experiments, this model still supports observable Gravitational Waves.
P Addesso - One of the best experts on this subject based on the ideXlab platform.
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first search for nontensorial Gravitational Waves from known pulsars
Physical Review Letters, 2018Co-Authors: B P Abbott, R Abbott, T D Abbott, M R Abernathy, K Ackley, C Adams, P Addesso, R X Adhikari, V B Adya, C AffeldtAbstract:We present results from the first directed search for nontensorial Gravitational Waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict Waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of Gravitational Waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.
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observation of Gravitational Waves from a binary black hole merger
Physical Review Letters, 2016Co-Authors: B P Abbott, F Acernese, R Abbott, T D Abbott, M R Abernathy, K Ackley, C Adams, P Addesso, T Adams, R AdhikariAbstract:On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient Gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak Gravitational-wave strain of $1.0 \times 10^{-21}$. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1 {\sigma}. The source lies at a luminosity distance of $410^{+160}_{-180}$ Mpc corresponding to a redshift $z = 0.09^{+0.03}_{-0.04}$. In the source frame, the initial black hole masses are $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$, and the final black hole mass is $62^{+4}_{-4} M_\odot$, with $3.0^{+0.5}_{-0.5} M_\odot c^2$ radiated in Gravitational Waves. All uncertainties define 90% credible intervals.These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of Gravitational Waves and the first observation of a binary black hole merger.
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observation of Gravitational Waves from a binary black hole merger
Vasconcellos C.A.Z. (ed.) Centennial of General Relativity: A Celebration, 2016Co-Authors: B P Abbott, F Acernese, R Abbott, T D Abbott, K Ackley, C Adams, P Addesso, T Adams, M Abernathy, R X AdhikariAbstract:On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient Gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak Gravitational-wave strain of 1.0×10^(−21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410 +160/−180 Mpc corresponding to a redshift z=0.09 +0.03/−0.04. In the source frame, the initial black hole masses are 36+5−4M_⊙ and 29+4−4M_⊙, and the final black hole mass is 62+4−4M⊙, with 3.0+0.5−0.5M_⊙c^2 radiated in Gravitational Waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of Gravitational Waves and the first observation of a binary black hole merger.
