Title: On the time lags of the LIGO signals Author: James Creswell, Sebastian von Hausegger, Andrew D. Jackson, Hao Liu, Pavel Naselsky
To date, the LIGO collaboration has detected three gravitational wave (GW) events appearing in both its Hanford and Livingston detectors. In this article we reexamine the LIGO data with regard to correlations between the two detectors. With special focus on GW150914, we report correlations in the detector noise which, at the time of the event, happen to be maximized for the same time lag as that found for the event itself. Specifically, we analyse correlations in the calibration lines in the vicinity of 35 Hz as well as the residual noise in the data after subtraction of the best-fit theoretical templates. The residual noise for the two more recent events, GW151226 and GW170104, exhibits equivalent behaviour with respect to each of their time lags. A clear distinction between signal and noise therefore remains to be established in order to determine the contribution of gravitational waves to the detected signals.
New gravity waves hit Earth after record-breaking trip through space
Researchers at the Institute for Gravitation and the Cosmos at Penn State provided leadership in this discovery, as well as in LIGO's previous detections. B.S. Sathyaprakash, the Elsbach Professor of Physics and professor of astronomy and astrophysics, played a key role in the characterization of the sources. He is one of the two leaders of the editorial process for the paper describing the discovery, which has been accepted for publication in the journal Physical Review Letters. Chad Hanna, assistant professor of physics and astronomy and astrophysics and Freed Early Career Professor at Penn State, served as the co-chair of LIGO's Compact Binary Coalescence Group, which detected the three gravitational waves discovered thus far. Read more
The Laser Interferometer Gravitational-Wave Observatory has made a third detection of gravitational waves, providing the latest confirmation that a new window in astronomy has opened. As was the case with the first two detections, the waves - ripples in spacetime - were generated when two black holes collided to form a larger black hole. The latest findings by the LIGO observatory, described in a new paper accepted for publication in Physical Review Letters, builds upon the landmark discovery in 2015 of gravitational waves, which Albert Einstein predicted a century earlier in his theory of general relativity. Read more
Gravitational wave detector prepares to peer into bizarre stars
Prepare for a big wave - a wave of gravitational waves. A mass of predictions from the latest meeting of the American Physical Society in Washington DC is shedding light on what's next for the massive LIGO collaboration. With two sets of colliding black holes in its net and another possible pair in its second run, LIGO, the world's first successful gravitational wave detector is finally ready to see the unexpected. LIGO's second run began on 30 November 2016. On 28 January, the team announced that it had seen two event candidates so far, which matches the expected rate of about one per month. Read more
Advanced Ligo gravitational wave hunt is green lit
One of the great physics experiments of our age looks ready to begin its quest. Scientists have held a dedication ceremony to inaugurate the Advanced Ligo facilities in the US. This pair of widely separated laboratories will be hunting for gravitational waves. Read more
Newly dedicated observatory to search for gravitational waves
Seeking to expand how we observe and understand the universe where we live, the National Science Foundation today helped dedicate the Advanced Laser Gravitational Wave Observatories (Advanced LIGO) at the LIGO Hanford facility in Richland, Wash. Read more
Echoes of the birth of the universe Results of cosmic analysis set new limits on gravitational waves that could have come from the Big Bang, and begin to constrain current theories about universe formation
An investigation by the LIGO (Laser Interferometer Gravitational-Wave Observatory) Scientific Collaboration, designed and operated by Caltech and MIT, and the Virgo Collaboration, has significantly advanced our understanding of the early evolution of the universe.
Gravitational Wave Observatory listens for echoes of universe's birth An investigation by a major scientific group headed by a University of Florida professor has advanced understanding of the early evolution of the universe. An analysis of data from the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, or LIGO, and the Virgo Collaboration has set the most stringent limits yet on the amount of gravitational waves that could have come from the Big Bang in the gravitational wave frequency band where LIGO can observe. In doing so, scientists have put new constraints on the details of how the universe looked in its earliest moments.
British-made technology will boost the search for elusive gravitational waves UK scientists are helping us edge ever closer to finding the mysterious, theorised ripples in the fabric of spacetime (known as gravitational waves) with the production of 25 new assemblies for the LIGO facility - a network of detectors designed to search for these elusive waves. Funded by the US National Science Foundation (NSF), LIGO also allows us to look inside the most violent events in the Universe and traces its exotic phenomena in great detail. By increasing the sensitivity of the LIGO detectors by a factor of ten, the upgrades will greatly increase our chances of finding gravitational waves and open a new observational window on the Universe to test our current theories and models.