Gravitation

High precision optical metrology for the LISA instrument

     The LISA project of gravitational waves detection has been selected in spring 2017 as a ‘Large’-class mission of the European Space Agency. 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.

35 nouveaux séismes cosmiques détectés par Virgo et LIGO

LIGO et Virgo ont rendu public leur 3ème catalogue GWTC-3 de détections, couvrant la période correspondant à la fin du troisième run d'observation dans leur configuration avancée. Les détecteurs ont observé 35 nouveaux événements d'ondes gravitationnelles entre novembre 2019 et mars 2020. Le nombre total de signaux gravitationnels détectés à ce jour par le réseau international des trois détecteurs d’ondes gravitationnelles flirte désormais avec la centaine.

DISENTANGLING AND CHARACTERIZING ASTROPHYSICAL GRAVITATIONAL WAVE SIGNALS WITH LISA

LISA is a space-based gravitational wave (GW) observatory that is planned for launch in 2034. It consists of three satellites in the free fall in the heliocentric orbit forming an equilateral triangle. Satellites exchange the laser light forming transponding interferometry allowing to detect GWs in the mHz band.  A plethora of gravitational-wave signals from different astrophysical sources is expected to be observed by LISA. These sources include galactic white dwarf binaries, extreme mass-ratio inspirals, massive black hole binaries, etc.

Massive black holes binaries as probes of the Universe.

Massive black holes are located in the centre of all massive galaxies. During the encounter of galaxies those black holes pair and, after some hardening period, become sources of gravitational waves (GWs).  Binaries at the early stage of inspiral emit almost monochromatic GWs and the population of massive black hole binaries (MBHBs) is the main source for the Pulsar Timing Array (PTA).  In PTA we use radio emission from the millisecond pulsars to detect GWs in the nano-Hz frequency band.

Disentangling and characterizing astrophysical GW signals with LISA

LISA is a space-based gravitational wave (GW) observatory which is planned for launch in 2034. It consists of three satellites in the free fall in the heliocentric orbit forming an equilateral triangle. Satellites exchange the laser light forming transponding interferometry allowing to detect GWs in the mHz band.  A plethora of gravitational-wave signals from different astrophysical sources is expected to be observed by LISA. These sources include galactic white dwarf binaries, extreme mass-ratio inspirals, massive black hole binaries, etc.

A Lunar Seismic and Gravitational Antenna (LSGA)

We propose a thesis for the study of the scientific potential and technical feasibility of a Lunar Seismic and Gravitational Antenna (LSGA). LSGA is a response to the call of ideas of ESA for a Lunar Lander. It concerns the deployment of an engineered fiber distributed acoustic sensor system (EFDAS) on the lunar surface, in complementarity and projected increase of sensitivity, to the Very Broad Band VBBZ Farside Seismic Suite (VBBZ-FSS).

Gravitation