Exploring novel data analysis methods for the detection and parameter estimation of gravitational waves observed by detectors like LIGO and LISA.
Gravitational waves are the last prediction of Einstein's theory of General Relativity, portraying as "ripples" in spacetime generated by spherically asymmetric acceleration of matter. On September 14, 2015, for the first time in human history, the LIGO Scientific Collaboration (LSC) directly detected a gravitational wave from the collision (merging) of two black holes, using a pair of 4-km long LIGO detectors in the United States. This event was named GW150914, and its detection won three LSC leaders the Nobel Prize of Physics in 2017. This ground-breaking discovery opened a completely new window to observe the Universe! By April 2020, the LIGO, Virgo, and KAGRA collaborations had collaboratively detected 90 gravitational waves, including the unprecedented observation of two merging neutron stars.
As with many discoveries, it opens more questions than it answers. Members of the Gravitational Wave Initiative are interested in what can we learn from gravitational wave signals with existing ground-based gravitational-wave detectors such as LIGO, Virgo, and KAGRA, and the next generation of ground-based detectors such as Cosmic Explorer and the Einstein Telescope, as well as the space-borne observatories like LISA.
Extracted from B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), 2016: LIGO measurement of the gravitational waves at the Hanford (left) and Livingston (right) detectors, compared to the theoretical predicted values. The top two plots show the strain, or amplitude of the wave as a function of time in the two detectors with noise. The second plots show the reconstructed signal with different techniques, including numerical relativity. The third plots show the noise residuals. Finally, the fourth plots show the frequency as a function of time. This "yellow banana” shape, indicating that the frequency grows with time, is characteristic of a binary waveform. It is called a chirp.
Distribution of LIGO-Virgo-KAGRA black holes and neutron star masses together with the black holes and neutron stars observed electromagnetically.[Credit: LIGO-Virgo-KAGRA, Aaron Geller, Northwestern]
GWI members working on gravitational wave data science include:
(See Our Members for contact links)