Researchers from IFAE, who participate in both Virgo and LIGO, contributed to different areas including support for operations, commissioning, data characterization and calibration of the LIGO and Virgo experiments and physics analysis, in addition to providing significant computing resources to the experiments via PIC . Their work supports the search for black-hole and neutron-star mergers and the improvement of detector sensitivity.

During O4, the detectors recorded hundreds of candidate gravitational-wave signals and operated with improved duty cycle and stability. The public alert system also enabled rapid community follow-up of transient events. The collaboration is now preparing for the next major upgrade period ahead of O5, which will further enhance sensitivity and expand the accessible volume of the Universe.

IFAE researchers will continue to contribute to the forthcoming upgrades (including the installation at Virgo of two new large instrumented baffles as designed and built at IFAE and further assisting in the control of the stray light inside the experiment), LIGO and Virgo operations and data analysis, and to the global effort to refine gravitational-wave astronomy.