15. A Riemann manifold Hamiltonian Monte Carlo (RMHMC) for binary neutron star parameter estimation.
M. Yann Bouffanais (Laboratoire APC)
The Hamiltonian Monte Carlo (HMC) is a sampling algorithm that eliminates a random walk in parameter space by applying Hamilton’s equations on the position and momentum of a fiducial particle. In this way, one is able to explore the posterior in a very efficient way, since information from the posterior is directly used to compute the dynamics of the particle at each step in its trajectory. ...
Sabrina D'Antonio (INFN Tor Vergata)
In the all-sky search for continuous gravitational waves emitted by spinning neutron stars, the most significant candidates are selected and subject to a follow-up step. The follow-up allows to strongly increase the detection confidence for real gravitational wave signals and to reject candidates of non-gravitational origin. The computational cost of the follow-up is an important issue as it...
M. Yoshinori Fujii (U. of Tokyo / National Astronomical Observatory of Japan)
We present expected fast sky localisation of coalescing binaries with a hierarchical search using three gravitational wave (GW) detectors, HLV (Hanford/Livingston/Virgo). A hierarchical search can be used with different sensitivity GW detectors, and is aimed at making effective use of the least sensitive detector’s information. In the hierarchical network, the less sensitive detectors are...
57. Hierarchical data-driven approach to fitting waveform models for non-precessing binary black holes to numerical data
Dr Sascha Husa (University of the Balearic Islands)
In previous work we have developed a method to systematically approach the problem of fitting a model to the 3-dimensional parameter space of non-precessing quasi-circular binary black holes, and applied it to construct accurate fits to final spin, radiated energy and peak luminosity, which avoid over-fitting. In this work we extend our approach to a phenomenological waveform model in the...
Prof. Tjonnie Li (The Chinese University of Hong Kong)
Recent discoveries of binary black holes by gravitational-wave detection hint at the opportunity of observing binaries containing neutron stars. Unlike with black holes alone, the presence of a neutron star can help us constrain the equation of state of ultradense matter. The feasibility of constraining the equation of state through gravitational-wave detections have typically been studied...
Mme Elena Massera (University of Sheffield-LIGO scientific collaboration)
The rapid analysis of gravitational-wave data is not trivial for many reasons, such as the non-stationary nature of the background noise in gravitational-wave detectors and the lack of a definite and exhaustive waveform models, especially for gravitational-wave burst signals. One active research area is based on the use of X-PIPELINE , a software package designed for performing autonomous...
Soichiro Morisaki (University of Tokyo)
Many researchers are trying to explain the dark sector in the universe by modifying general relativity. Recently, a new cosmological scenario which explains the existence of dark matter by adding an extra scalar field in GR, called asymmetron scenario, was proposed. In this theory, the scalar field gets nontrivial values inside highly dense matter, such as neutron stars, and weaken...
12. Development of a Wide-Field CMOS Camera: Tomo-e Gozen and Contributions to EM Follow-up Observations of Gravitational Wave Events
Ryou Ohsawa (Institute of Astronomy, University of Tokyo)
We are developing a wide-field CMOS camera, Tomo-e Gozen, which will be mounted on the $105\,$cm Schmidt telescope at the Kiso Observatory, the University of Tokyo. The Tomo-e Gozen camera is composed of four camera modules, each of which is equipped with 21 CMOS image sensors with $1\,$arcsec/pix. The Tomo-e Gozen captures a sky of about 20-sq degree without any overhead due to readout time....
46. New parameter estimation method being free from the bias depending on sky region for targeted GW search
M. Kenji Ono (ICRR)
The first direct detection of a GW has been archived. In the next stage, it is important for a GW astronomy and cosmology to observe GW signal all over the sky by the use of global network of the interferometers. Even aLIGO-Virgo-KAGRA network, however, provides biased accuracy of the parameter estimation depending strongly on the sky location of a GW. In order to perform the parameter...
44. Setting up a direct search for continuous gravitational wave signals using the Band Sample Data collection
Mlle Ornella Juliana Piccinni (University of Rome "La Sapienza" - INFN)
We present a preliminary study for the setup of a directed search for continuous gravitational waves, based on the so-called Band Sample Data (BSD) collection of LIGO and Virgo data. In directed searches for continuous wave signals, the sky location of the source is well-known while the frequency and the spin-down parameters are unknown. Using the BSD collection it is possible to apply the...
28. Estimation of starting times of quasi-normal modes in ringdown gravitational waves with the Hilbert-Huang transform
M. Kazuki Sakai (Nagaoka University of Technology)
We propose a method of determining the starting time of the quasi-normal mode (QNM) and calculating the QNM frequency and amplitude of gravitational waves from binary black hole merger. Our method determines the starting time and calculates the parameters by regression analysis of time evolutions of the amplitude and frequency calculated by means of the Hilbert-Huang transform. We apply it to...
akshat singhal (GSSI)
Rapidly rotating neutron stars with non-axisymmetric deformations are an interesting type of continuous-wave source for the LIGO-Virgo detectors. Within the sensitivity band of these detectors, more than half of the known pulsars in our galaxy are in binary systems. Signals coming from binary sources are Doppler modulated due to the source orbital motion, which spreads the signal in several...
M. Yukio Tomozawa (University of Michigan)
Dark energy is not needed to explain the rate of acceleration of the universe. The improvement in the accuracy of time delay experiment data combined with the physical metric produces the correct model to prove/predict the rate of acceleration of the universe. The measurement of time delay experiment data of the solar system has been improved by the use of the Cassini satellite as a...
Mlle Maria Concetta Tringali (University of Trento and INFN-TIFPA)
Gravitational wave (GW) emission from a binary neutron star (BNS) coalescence carries the signature of its complex dynamics and of neutron star (NS) properties such as the equation of state (EoS). In particular, the extraction and characterization of the signal emitted in the post-merger phase by the massive NS remnant offers an opportunity to strongly constrain the behaviour of matter at...
16. Application of a zero-latency whitening filter to compact binary coalescence gravitational-wave searches
M. Leo Tsukada (The University of Tokyo)
We examine the performance of a zero-latency whitening filter in a detection pipeline for compact binary coalescence (CBC) gravitational-wave (GW) signals. We find that the filter reproduces sufficiently consistent signal-to-noise ratio (SNR) for both noise and artificial GW signals (called injections) with the results of the original high latency and phase preserving filter. Additionally, we...
M. Julian Westerweck (AEI Hannover)
We show details of the AEI search for black hole echoes in LIGO public data. Echoes of gravitational waves of a compact binary merger provide a potential way to test alternative models of black holes. Abedi et al. claimed in 2016 to have found evidence of these echoes in LIGO public data. We have developed an extended analysis pipeline to evaluate these claims. This includes extending the...
Dr Takaaki Yokozawa (Osaka City University)
Authors : Takaaki Yokozawa on the behalf of KAGRA collaboration KAGRA detector had test run in March and April, 2016 with room temperature and simplified configuration (called iKAGRA run). At the end stage of this run, we injected some waveforms to end test mass through arm length control system, which is called hardware injection. Hilbert-Huang Transform (HHT) is one of the time-frequency...
49. Looking for truffles in trash: The new DMoff veto in Einstein@Home searches for continuous gravitational waves
Dr Sylvia Zhu (Albert Einstein Institute)
In the current era of the advanced LIGO and Virgo detectors, we are closer than ever to detecting the first continuous gravitational wave signal. At the same time, our searches are becoming increasingly sensitive, to both astrophysical sources and the detector artifacts that can mimic the signals that we search for. We developed a straightforward veto to quickly and effectively exclude signal...