European cooperation on gravitational waves endorsed in Pisa

24 March 2022

In Pisa on Tuesday, the signatures were put on an agreement by which NWO-I becomes an official member of EGO, the European cooperation in the field of gravitational waves.

EGO now has three parties: the Italian INFN, the French CNRS and the Dutch institute organisation NWO-i. In practice, the National Institute for Subatomic Physics Nikhef, an NWO institute, is the Dutch partner in the collaboration.

Nikhef director Stan Bentvelsen signed the agreement on behalf of the Netherlands in Pisa. Formally, it already went into effect in 2021, but corona has since prevented the formal ratification. “An emotional moment,” said EGO director Stavros Katsanevas at the ceremony. He pointed to the strong scientific and personal ties between the participants.

The Netherlands was already an observer at EGO. Nikhef has a leading role in the Virgo gravity wave observatory near Pisa.

Gravity waves they subtle ripples of space itself that, according to Einstein’s theory of relativity, can occur when very compact heavy objects, such as black holes, collide. This was first observed in 2015, then with the LIGO detectors in the US.

Since then, LIGO and Virgo together have observed many dozens of signals, both of colliding black holes and collisions with neutron stars.

Within Europe, preparations are now underway for the construction of a new and underground detector for gravitational waves, the Einstein Telescope. Proposals to this end have been submitted in the European context. In addition to Sardinia, the border region of South Limburg is a potential construction site.