60 research outputs found
Searching data for periodic signals
We present two statistical tests for periodicities in the time series. We
apply the two tests to the data taken from Glasgow prototype interferometer in
March 1996. We find that the data contain several very narrow spectral
features. We investigate whether these features can be confused with
gravitational wave signals from pulsars.Comment: 7 pages, 2 figure
Estimation of Parameters of Gravitational Waves from Pulsars
The problem of search for nearly periodic gravitational wave sources in the
data from laser interferometric detectors is discussed using a simple model of
the signal. Accuracies of estimation of the parameters and computational
requirements to do the search are assessed.Comment: 6 pages, Latex, 1 figure, moriond.sty macr
The First Detection of Gravitational Waves
This article deals with the first detection of gravitational waves by the
advanced Laser Interferometer Gravitational Wave Observatory (LIGO) detectors
on 14 September 2015, where the signal was generated by two stellar mass black
holes with masses 36 and 29 that merged to form a 62
black hole, releasing 3 energy in gravitational waves,
almost 1.3 billion years ago. We begin by providing a brief overview of
gravitational waves, their sources and the gravitational wave detectors. We
then describe in detail the first detection of gravitational waves from a
binary black hole merger. We then comment on the electromagnetic follow up of
the detection event with various telescopes. Finally, we conclude with the
discussion on the tests of gravity and fundamental physics with the first
gravitational wave detection event.Comment: 20 pages, 9 figures, Published in a special issue of Universe
"Varying Constants and Fundamental Cosmology
Gravitational-Wave Data Analysis. Formalism and Sample Applications: The Gaussian Case
The article reviews the statistical theory of signal detection in application
to analysis of deterministic gravitational-wave signals in the noise of a
detector. Statistical foundations for the theory of signal detection and
parameter estimation are presented. Several tools needed for both theoretical
evaluation of the optimal data analysis methods and for their practical
implementation are introduced. They include optimal signal-to-noise ratio,
Fisher matrix, false alarm and detection probabilities, \F-statistic,
template placement, and fitting factor. These tools apply to the case of
signals buried in a stationary and Gaussian noise. Algorithms to efficiently
implement the optimal data analysis techniques are discussed. Formulas are
given for a general gravitational-wave signal that includes as special cases
most of the deterministic signals of interest.Comment: Revised version of 2006-07-26; published version available at
http://www.livingreviews.org/lrr-2005-
Naked strong curvature singularities in Szekeres space-times
We investigate the occurrence and nature of naked singularities in the
Szekeres space-times. These space-times represent irrotational dust. They do
not have any Killing vectors and they are generalisations of the
Tolman-Bondi-Lemaitre space-times. It is shown that in these space-times there
exist naked singularities that satisfy both the limiting focusing condition and
the strong limiting focusing condition. The implications of this result for the
cosmic censorship hypothesis are discussed.Comment: latex, 9 page
Search for Postmerger Gravitational Waves from Binary Neutron Star Mergers Using a Matched-filtering Statistic
In this paper, we present a new method to search for a short postmerger
gravitational-wave signal following the merger of two neutron stars. Such a
signal could follow the event GW170817 observed by LIGO and Virgo detectors.
Our method is based on a matched filtering statistic and an approximate
template of the postmerger signal in the form of a damped sinusoid. We test and
validate our method using postmerger numerical simulations from the CoRe
database. We find no evidence of the short postmerger signal in the LIGO data
following the GW170817 event and we obtain upper limits. For short postmerger
signals investigated, our best upper limit on the root sum square of the
gravitational-wave strain emitted from 1.15 kHz to 4 kHz is
at 50% detection
efficiency. The distance corresponding to this best upper limit is 4.64 Mpc.Comment: LaTeX, 28 pages, 15 figure
Optimal filtering of the LISA data
The LISA time-delay-interferometry responses to a gravitational wave signal are rewritten in a form that accounts for the motion of the LISA constellation around the Sun; the responses are given in closed analytic forms valid for any frequency in the band accessible to LISA. We then present a complete procedure, based on the principle of maximum likelihood, to search for stellar-mass binary systems in the LISA data. We define the required optimal filters, the amplitude-maximized detection statistic (analogous to the Ƒ statistic used in pulsar searches with ground-based interferometers), and discuss the false-alarm and detection probabilities. We then test the procedure in numerical simulations of gravitational-wave detection
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