LIGO

In October 2018, the IGFAE joined the LIGO Scientific Collaboration (LSC), an initiative focused on gravitational wave (GW) science. Gravitational waves are ripples or oscillations in space-time predicted by Einstein more than 100 years ago and observed for the first time by the Laser interferometer Gravitational-Wave Observatory (LIGO) in September 2015.

These first gravitational waves detections have been recognized by, among others, the 2016 Special Breakthrough Prize in Fundamental Physics for the LSC and Virgo collaborations – including two IGFAE members – and the 2017 Nobel Prize in Physics for three pioneering LIGO scientists.

After the detection of 90-odd gravitational wave signals over the first three observing runs of the Advanced LIGO and Virgo detectors up to 2020, the data-sharing network has now been enlarged with the newly commissioned cryogenic KAGRA detector in Japan.  The 4th observing run began in May 2023 with increased network sensitivity, and is expected to yield hundreds more detections over the next 1.5 years.

After being awarded with a Maria de Maeztu Unit of Excellence in 2017, researchers at IGFAE identified GW science as a research line with particularly high potential impact, particularly in connection with Multi-Messenger Astrophysics. This is a branch of astrophysics that aims at exploiting the detection of different types of signals (photons, GW, cosmic-rays, neutrinos) to enhance and complement the information from astrophysical sources. The new line of research opened at IGFAE also has synergies with the current activities of the Institute, in particular with the strong theoretical involvement in many aspects of gravity, the use of gravitational waves as probes of ultra-dense nuclear matter in neutron stars, as well as with experimental activities in the framework of the Pierre Auger Observatory, the largest and most accurate ultra-high-energy cosmic-ray detector in the world.