Gravitational waves

LISA (Laser Interferometer Space Antenna) is a space mission of the European Space Agency aimed at detecting low-frequency gravitational waves (GW), between 0.02 mHz and 1 Hz. LISA consists of three satellites forming a quasi-equilateral triangle 2.5 million km on each side, exchanging laser beams to measure variations in distance on the order of tens of picometers. The mission will observe a wide variety of sources, including the coalescence of supermassive black holes and stochastic AGO backgrounds of cosmological and astrophysical origin. These measurements will enable us to test general relativity, in particular the “no-hair” theorem for Kerr-type final black holes, and to study the primordial Universe.

The DPhP is one of two Principal Investigator (PI) laboratories in France. Together with the IRFU and other French laboratories, it contributes to ground test equipment, data processing and scientific exploitation. IRFU is developing the laser injectors for the interferometric test benches (MIFO and ZIFO) and supplying the hardware simulator for the reference mass, the stable structure and the thermomechanical studies associated with the interferometric detection system.

The mission requires powerful computing infrastructures and sophisticated algorithms to reduce noise and extract parameters from the numerous sources. DPhP’s LISA group is developing methods to characterize instrumental noise and analyze data, integrating complex simulations and techniques such as delayed interferometry. The mission has been adopted by ESA in 2024, and is scheduled for launch in 2035. Instrumental and flight model tests are scheduled between 2027 and 2030.

Contact: Antoine Petiteau