The gravitational-wave detectors outputs from the LIGO and Virgo collaborations have been a source of scientific results of prime importance in various domains such as astrophysics, cosmology or fundamental physics. With the upgrades of the detectors and their improved sensitivities, new challenges are set for these instruments calibration. A calibration method based on the local variations of the Newtonian gravitational field could be the next absolute reference of calibration for the interferometers network. We report new tests of Newtonian calibrators (NCal) on the Advanced Virgo detector performed during the LIGO-Virgo observing run O3. The NCal-induced strain on a mirror of the interferometer has been computed both using analytical calculations and numerical simulations with results in very good agreement. The strains given by the numerical model have been used to analyse the data of the NCals and have been compared to the reference method of calibration using photon radiation pressure. New methods to measure the NCal to mirror distance and the NCal offset with respect to the plane of the interferometer using two NCals are also presented and used to correct the NCal data which improves the agreement with the current Advanced Virgo reference of calibration.
As the sensitivities of LIGO, Virgo and KAGRA detectors improve, calibration of the interferometers output is becoming more and more important and may impact scientific results. For the observing run O3, Virgo used for the first time photon calibrators (PCal) to calibrate the interferometer, using radiation pressure of a modulated auxiliary laser beam impinging on the Advanced Virgo end mirrors. Those optical devices, also used in LIGO, are now the calibration reference for the global gravitational wave detectors network. The intercalibration of LIGO and Virgo PCals, based on the same absolute…
The ongoing improvements of the advanced gravitational wave (GW) detectors are setting challenging requirements on instrument calibration. We report tests of a calibration technique, based on the well-known gravitation force, which has been applied for the first time on a large interferometer. The results obtained with Advanced Virgo are in good agreement with the predictions and with the usual calibration method. This technique is expected to lead to accurate absolute calibration at the sub-percent level in the coming years, matching the needs of the blooming GW science.
A Tale of Two Calibrators: Comparing Newtonian and Photon Calibration in Advanced LIGO after the Third Observing Run
The Australian National University（澳大利亚国立大学）；University of Washington（华盛顿大学）；LIGO Hanford Observatory（LIGO汉福德天文台）；LIGO Livingston Observatory（LIGO利文斯顿天文台）；Missouri Institute of Science and Technology（密苏里科技大学）；Kenyon College（肯扬学院）
The precise calibration of the strain readout of the LIGO gravitational wave observatories is paramount to the accurate interpretation of gravitational wave events. This calibration is traditionally done by imparting a known force on the test masses of the observatory via radiation pressure. Here we describe the implementation of an alternative calibration scheme: the Newtonian Calibrator. This system uses a rotor consisting of both quadrupole and hexapole mass distributions to apply a time-varying gravitational force on one of the observatory's test masses. The force produced by this rotor ca…
Estimation of systematic error from bulk deformation of end test mass induced by photon calibrator for LIGO post-O5 gravitational wave projects
National Central University（中央大学）；High Energy Accelerator Research Organization (KEK)（高能加速器研究机构（KEK））；Academia Sinica（中央研究院）；Kenyon College（肯扬学院）；LIGO Hanford Observatory（LIGO汉福德天文台）
We use equations of motion containing gravitational radiation-reaction terms through 4.5 post-Newtonian order to calculate the late-time eccentricities of inspiraling binary systems of non-spinning compact bodies as they cross the detection threshold of ground-based gravitational-wave interferometers. The initial eccentricities can be as large as 0.999. We find that the final eccentricities are systematically smaller than those predicted by the leading quadrupole approximation, by as much as 30 percent for a 300 solar mass binary crossing the LIGO/Virgo detection threshold at 10 Hz, or eight p…
We summarize the four tests of general relativity carried out using the ten binary black hole signals detected by Advanced LIGO and Advanced Virgo and included in their first catalog, GWTC-1. These events provide unprecedented opportunities for testing the predictions of general relativity for the gravitational waveforms from these highly dynamical, strong-field events. The first two tests check the consistency of the residuals with noise and the consistency of the low- and high-frequency parts of the signal. The other two tests check that parameterized deviations in the waveform model---inclu…
Searching for departures from general relativity (GR) in more than one post-Newtonian (PN) phasing coefficients, called a \emph{multi-parameter test}, is known to be ineffective given the sensitivity of the present generation of gravitational-wave (GW) detectors. Strong degeneracies in the parameter space make the outcome of the test uninformative. We argue that Principal Component Analysis (PCA) can remedy this problem by constructing certain linear combinations of the original PN parameters that are better constrained by gravitational-wave observations. By analyzing binary black hole events …
Analytical Estimate of Atmospheric Newtonian Noise Generated by Acoustic and Turbulent Phenomena in Laser-Interferometric Gravitational Waves Detectors
Dimensional regularization is applied to the computation of the gravitational wave field generated by compact binaries at the third post-Newtonian (3PN) approximation. We generalize the wave generation formalism from isolated post-Newtonian matter systems to d spatial dimensions, and apply it to point masses (without spins), modelled by delta-function singularities. We find that the quadrupole moment of point-particle binaries in harmonic coordinates contains a pole when epsilon = d-3 -> 0 at the 3PN order. It is proved that the pole can be renormalized away by means of the same shifts of the …
Probing Yukawa Gravity with Modulated Newtonian Cancellation in the CHRONOS Detector
National Central University（中央大学）；Center for High Energy and High Field (CHiP), National Central University（中央大学高能高场中心）；Institute of Physics, Academia Sinica（中央研究院物理研究所）；Institute of Particle and Nuclear Studies, High Energy Acceleration Research Organization (KEK)（高能加速器研究机构粒子核研究部）
Parameter estimation of neutron star-black hole binaries using an advanced gravitational-wave detector network: Effects of the full post-Newtonian waveform
Gravitational waves from compact binaries inspiralling along post-Newtonian accurate eccentric orbits: Data analysis implications
沿偏心轨道旋转的致密双星是地基激光干涉仪的引力波源。我们探索的损失，在事件发生率时，从紧凑的二进制文件，沿着后牛顿精确偏心轨道与某些明显的非最佳搜索模板的灵感搜索GW。对于本分析，具有2.5后牛顿精确轨道演化的GW信号按照[T. Damour，A. Gopakumar和B. R. Iyer，Phys. Rev. \textbf{70}，064028（2004）]。我们证明了搜索模板，模型在规范不变的方式GWs从紧凑的二进制inspirling qudrupolar辐射反应下沿2 PN精确的圆形轨道是非常有效的捕捉我们有点现实的GW信号。然而，基于绝热、完全绝热和规范依赖的完全非绝热近似的三种类型的搜索模板在[P. Ajith，B. R.伊耶角A. K. Robinson和B. S. Sathyaprakash，%``A new class of post-Newtonian approximants to the dynamics of inspiralling compact binaries：Test-mass in the Schwarzschild spacetime，'' Phys. Rev. D { \bf 71}，044029（2005）]，与四极辐射反应下的圆形内旋相关，发现在捕获上述偏心信号方面效率低下。我们的结论是，将需要进一步的调查，以探测各种类型的PN准确的…
We present a revised version of Peters' (1964) time-scale for the gravitational-wave (GW) induced decay of two point masses. The new formula includes the effects of the first-order post-Newtonian perturbation and additionally provides a simple fit to account for the Newtonian self-consistent evolution of the eccentricity. The revised time-scale is found by multiplying Peters' estimate by two factors, $R(e_0)= 8^{1-\sqrt{1-e_0}}$ and $Q_{\rm f}(p_0) = \exp \left(2.5 (r_{\rm S}/p_0) \right)$, where $e_0$ and $p_0$ are the initial eccentricity and periapsis, respectively, and $r_{\rm S}$ the Schw…
While most binary inspirals are expected to have circularized before they enter the LIGO/Virgo frequency band, a small fraction of those binaries could have non-negligible orbital eccentricity depending on their formation channel. Hence, it is important to accurately model eccentricity effects in waveform models used to detect those binaries, infer their properties, and shed light on their astrophysical environment. We develop a multipolar effective-one-body (EOB) eccentric waveform model for compact binaries whose components have spins aligned or anti-aligned with the orbital angular momentum…
Dark Matter Clumps as Sources of Gravitational-Wave Glitches in LIGO/Virgo/KAGRA data
International Center for Advanced Studies, Universidad de San Martin and CONICET（国际高级研究中心，圣马丁大学及阿根廷科学技术研究委员会）；Illinois Center for Advanced Study of the Universe & Department of Physics, University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校宇宙高级研究中心及物理系）；Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）；Center for AstroPhysical Surveys, National Center for Supercomputing Applications（超级计算应用国家中心天体物理调查中心）
The waveform of a compact binary coalescence is predicted by general relativity. It is therefore possible to directly constrain the response of a gravitational-wave (GW) detector by analyzing a signal's observed amplitude and phase evolution as a function of frequency. GW signals alone constrain the relative amplitude and phase between different frequencies within the same detector and between different detectors. We analyze GW170817's ability to calibrate the LIGO/Virgo detectors, finding a relative amplitude calibration precision of approximately $\pm20\%$ and relative phase precision of $\p…
Gravitational-wave observations provide a unique opportunity to test general relativity (GR) in the strong-field and highly dynamical regime of the theory. Parametrized tests of GR are one well-known approach for quantifying violations of GR. This approach constrains deviations in the coefficients of the post-Newtonian phasing formula, which describes the gravitational-wave phase evolution of a compact binary as it inspirals. Current bounds from this test using LIGO/Virgo observations assume that binaries are circularized by the time they enter the detector frequency band. Here, we investigate…
After a short review of prominent properties of gravitational waves and the newly born gravitational astronomy, we focus on theoretical aspects. Analytic approximation methods in general relativity have played a crucial role in the recent discoveries of gravitational waves. They are used to build theoretical template banks for searching and analyzing the signals in the ground-based detectors LIGO and Virgo, and, further ahead, space-based LISA-like detectors. In particular, the post-Newtonian approximation describes with high accuracy the early inspiral of compact binary systems, made of black…
Advanced methods for computing perturbative, quantum-gravitational scattering amplitudes show great promise for improving our knowledge of classical gravitational dynamics. This is especially true in the weak-field and arbitrary-speed (post-Minkowskian, PM) regime, where the conservative dynamics at 3PM order has been recently determined for the first time, via an amplitude calculation. Such PM results are most relevantly applicable to relativistic scattering (unbound orbits), while bound/inspiraling binary systems, the most frequent sources of gravitational waves for the LIGO and Virgo detect…
