Master defense by James Creswell – University of Copenhagen

Master defense by James Creswell

Analysis of gravitational Waves from binary Black Hole Mergers

The experimental detection of gravitational waves is an important breakthrough in physics and astronomy. The Laser Interferometer Gravitational Wave Observatory (LIGO) and other upcoming experiments collect data with increasing sensitivity, but identifying and extracting the gravitational wave signals remains a challenging task in the presence of non-stationary and non-Gaussian detector noise. Statistical techniques for analysing gravitational wave data are reviewed and their limitations considered. The first direct observation of gravitational waves from a binary black hole merger, GW150914, is closely examined. A model-independent method for extracting gravitational wave signals based on the redundancy of two or more detectors is presented and used to assess the quality of theoretical templates for GW150914. The features of degeneracy that exist in the binary black hole parameter space are described. High similarity between waveforms is found across broad regions of the parameter space in the vicinity of GW150914.