Gravitation

La mission spatiale LISA, menée par l’Agence Spatiale Européenne, vient d’être adoptée par le Science Program Committee de l’Agence Spatiale Européenne ! Cette décision ouvre la voie à la conception et fabrication de cette ambitieuse mission spatiale scientifique, devant décoller en 2034-2035.
 
The detection of the binary neutron star merger GW170817 demonstrated that it was possible to infer the nuclear equation of state of the neutron starts, and constrain the mass-radius relation.  This internship will used a machine learning based algorithm developed at APC to test different equation of state predictions using current 2G and future 3G gravitational wave detectors.

Extreme mass ratio inspirals (EMRI) are one of the most exciting gravitational-wave sources the Laser Interferometer Space Antenna (LISA) will detect. They are made of compact objects evolving in the highly curved spacetime around Massive Black Holes (MBH). As such, they are exquisite probes of the strong regime of gravity. EMRIs emit gravitational-wave signals that typically feature 105 orbit cycles and can last one year in the observation window.

The proposed thesis subject is focused on the global validation process of the instrument metrological performance. Preliminary concepts exist for the various optical metrology test benches that will be required measure the instrumental characteristics. Obviously, the full constellation cannot be tested in flight conditions on ground. The instrument validation will therefore rely on a ingenious combination of specific measurements performed on the different subsystems, as well as the results obtained with specifically designed lab experiments.
International Pulsar Timing Array is a consortium of four collaborations working on detecting gravitational waves (GWs) in the nano-Hz band. The analysis of the third combined dataset of radio observations from 9 worldwide telescopes will start at the end of 2023. We are searching for GWs from a population of supermassive black hole binaries (SMBHBs). The expected signal could be decomposed into two components: the stochastic signal that is the result of an incoherent superposition of thousands of weak signals and the resolvable signal(s) from particularly massive and nearby binaries.

Second generation gravitational wave (GW) detectors opened era of gravitational wave astronomy with the first GW detection in 2015 and are now approaching their design sensitivity. During the 3 past observations runs, they detected 90 GW signals produced by the merging of binary compact objects, providing a wealth of scientific results ranging from the general relativity, to astrophysics and cosmology.