The detectors are now being brought online and will begin the search for gravitational waves, with unprecedented accuracy, later this year.
Gravitational waves are tiny ripples in space-time that are emitted as a result of violent cosmic events, such as exploding stars and merging black holes. These waves were first predicted by Albert Einstein in 1916 as a consequence of his general theory of relativity, but have yet to be detected directly.
As they travel towards Earth, these ripples bring with them information about their origins and about the nature of gravity that cannot be obtained by other astronomical tools.
It is believed the detection of gravitational waves will usher in a new era of astronomy, allowing researchers to examine the last minutes of the lives of black holes, as well as provide a snapshot of the Universe just a fraction of a second after the Big Bang.
Researchers at the University's School of Physics and Astronomy have used large-scale, state-of-the-art computer simulations of black-hole collisions to produce theoretical models of gravitational waves.
Professor B. S. Sathyaprakash, from the University's School of Physics and Astronomy, stated: "Advanced LIGO will open a new window for us to observe violent processes in the Universe, such as black holes colliding at near the speed of light. At Cardiff University we hope to use these observations to understand the nature of space-time and matter under extreme conditions, and to test Einstein's theory of gravity when gravitational fields become super strong."
Dr. Stephen Fairhurst, who is also at the School of Physics and Astronomy, stated: "The operation of Advanced LIGO will herald the beginning of gravitational wave astronomy. We will make use of the Cardiff University supercomputer to search through the detector data to identify the tell-tale signs of a gravitational wave signal."
The Advanced LIGO project consists of interferometric gravitational-wave detectors at two sites, one in Hanford, Washington State, USA and one in Livingston, Louisiana, USA.
Each of the 4-km-long L-shaped interferometers uses a laser split into two beams that travels back and forth down long arms. The beams are used to precisely monitor the distance between configured mirrors. According to Einstein's theory, this distance will change very slightly when a gravitational wave passes by.
The upgrade to the instruments will increase their sensitivity by a factor of 10 and provide a 1,000-fold increase in the number of astrophysical candidates for gravitational wave signals. The upgraded instruments will start taking data in the autumn of 2015.
The inauguration ceremony, which was taking place at the Hanford detector site, featured a number of speeches from key figures involved in the LIGO Scientific Collaboration.
Caltech's David H. Reitze, executive director of the LIGO project, stated: "We've spent the past seven years putting together the most sensitive gravitational-wave detector ever built. Commissioning the detectors has gone extremely well thus far, and we are looking forward to our first science run with Advanced LIGO beginning later in 2015. This is a very exciting time for the field."
France Córdova, director of the National Science Foundation, the main funders of the LIGO project, stated: "Advanced LIGO represents a critically important step forward in our continuing effort to understand the extraordinary mysteries of our universe. It gives scientists a highly sophisticated instrument for detecting gravitational waves, which we believe carry with them information about their dynamic origins and about the nature of gravity that cannot be obtained by conventional astronomical tools."