Date of Award
2008
Degree Type
Thesis
Degree Name
Master of Science
Program
Astronomy
Supervisor
Dr. Sreeram Valluri
Second Advisor
Dr. Shantanu Basu
Third Advisor
Dr. David F. Gray
Abstract
The direct detection of Gravitational Waves (GWs) is one of the most challenging problems in experimental gravitation today. It warrants the use of highly advanced large laser interferometers such as LIGO, VIRGO, LISA, TAMA 300, GEO 600 and AIGO. The analysis of the data from such instruments requires and combines the expertise from a multitude of scientific disciplines. The verification of a detected signal demands an effective way to distinguish the source signal from the background noise. Such a study is required for an all-sky search to determine the φ and θ angles on the sky of gravitational wave sources and their frequencies. In this thesis is presented analytical solutions and associated numerical approximations for the inner products employed in matched filtering using templates, a form of pattern recognition, applied to a GW pulsar signal. An exact closed-form expression for the inner products is rigourously derived using the special functions of mathematical physics. The inner products involve reciprocal Eulerian gamma functions, which occur in the study of many diverse phenomena. The spectral noise density of the VIRGO GW detector is shown to be amenable to analysis. Spectral noise densities like those for LIGO and GEO 600, although different and in a slightly more restricted frequency band, are likewise amenable. Numerical computation of the inner products, estimates of the computational time of the solution on serial and parallel computers, and the efficiency of the resulting algorithms are studied. The fitting factor that indicates the goodness of fit between a signal and a template is given in closed-form and computed numerically. The numerical plots display an approximate symmetry in the template φ and θ domain. Threshold crossing statistics are found, and the probability that a template is within a given radius of the signal is studied.
Recommended Citation
Normandin, Marc Eric, "Pattern Recognition of a Gravitational Wave Pulsar Signal" (2008). Digitized Theses. 4818.
https://ir.lib.uwo.ca/digitizedtheses/4818