Gravitation

Revealing the progenitors of GW mergers with neural networks

Accelerating stellar evolution models with neural networks, and application to the formation and evolution of astrophysical sources detected by LIGO/Virgo

Massive Stars Live in Pairs… Two major revolutions have transformed our understanding of stellar evolution. The first was the realization that most massive stars (over 75%) evolve within binary systems (Sana et al., 2012).

Search for massive black hole binaries in LISA data

   Merging massive black hole binaries (MBHBs) are important gravitational wave (GW) sources for the future space-based observatory LISA. The GW signal from the merger will be detected throughout the entire Universe. Characterization of the GW signal allows us to infer masses and spins of MBHs, the position of the source in the sky and the distance.  This information will allow us to understand the mechanism of MBHs formation and their evolution through cosmic history. 

Dirty Extreme Mass Ratio Inspirals

LISA -- Laser Interferometer Space Antenna -- will be launched in 2035 and will observe gravitational wave (GW) sources in the frequency range 0.1-100 mHz. Extreme mass ratio inspirals (EMRIs) are one of the prime sources for LISA. As a result of N-body interaction of stellar remnants in the galactic nuclei, a compact object, (CO), (a stellar mass black hole or a neutron star) could be thrown into a very eccentric orbit passing near a massive black hole (MBH).

Contribution to the LISA test campaign and in-orbit performance modeling

The LISA project of gravitational waves detection has been selected in January 2024 by the European Space Agency as the third ‘Large’ mission of the ‘Cosmic Vision’ program, with a expected launch date in 2035. This mission relies on the capability to measure, using laser interferometry, the distance fluctuations between satellites 2.5 Mkm apart, with a picometer accuracy on seconds to hours timescales.

Searching for gravitational waves from space: disentangling the source confusion

 LISA (Laser Interferometer Space Antenna) is a low-frequency gravitational wave observatory (0.1 mHz - 1 Hz) to be launched by ESA in 2035. It aims to observe several populations of relativistic binary stars: the white dwarf binaries in our Galaxy, super-massive black holes in coalescence, stellar-mass black holes captured by super-massive black holes in galactic nuclei, etc. In addition, we hope to observe stochastic gravitational wave signals from the primordial Universe.

La mission LISA adoptée!

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.
 

Inferring the nuclear equation of state using binary neutron star mergers

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.
Gravitation