The French activities for LISA (Laser Interferometer Space Antenna) mission include assembly, integration, validation and testing of the payload by a consortium of several partners led by CNES.
SYRTE has developed for several years a laser activity for the different tests and interferometric measures realized by the consortium. A partnership with eXail led to a major technological step in the...
In pursuit of observing a stochastic gravitational wave background (SGWB) with LISA, it is crucial to investigate the spectral separability of cosmological, astrophysical backgrounds, and galactic foreground in order to make accurate estimations.
Our objective is to determine the observability of a cosmological background, considering the predicted astrophysical background and galactic...
La contribution française (hardware) au sein du consortium LISA se trouve principalement dans le développement de bancs de test destinés à caractériser les bancs optiques au cœur de l’instrument LISA.
Pour ce faire, un ensemble de démonstrateurs ont été développés afin d’acquérir une expertise dans le domaine de l’interférométrie hétérodyne à basse fréquence, dont le banc optique de...
The now dismissed FF-OGSE was aimed at measuring the Tilt-To-Length coupling on LISA's benches. Its "active" core is the so-called FOGOB optical bench. It delivers a reference beam (REF) and an angular jittering beam (Rx), which are used to probe the longitudinal optical path length variations induced by the Rx tilt at the MOSA level. Such coupling is connected to the internal misalignments...
One of the science objectives of LISA is to probe fundamental physics. With the expected large SNR of the coalescence of SMBHB we hope to test General Relativity. Using the full IMR waveform we study the detectability of higher harmonics. With Bayesian analysis, we can discriminate models with different harmonics. Omitting harmonics not only diminishes the SNR but can also lead to biased...
Recently, the search for departures from the symmetries of General Relativity has received significant attention in the literature. In this talk, I outline the techniques for probing the nature of spacetime symmetries using the generation stage of gravitational waves. By using a generic effective-field theory, I show our solution scheme of the modified Einstein equations and I write down the...
Extreme mass-ratio inspirals (EMRIs) are one of the most important sources of gravitational waves (GWs) that will be detected by LISA. Similar to compact binary mergers detected by current GW detectors, EMRIs can be used as cosmic rulers to probe the expansion of the Universe and our current cosmological paradigm, the $\Lambda$CDM model. Modified gravity theories can affect the propagation of...
La mesure de la lumière parasite est un enjeu de premier plan dans
l'intégration de tout interféromètre. C'est le cas des interféromètres
dédiés à la géodésie spatiale, et bien sûr des interféromètres de la
mission LISA. Le "SL-OGSE" a été conçu pour mesurer la lumière parasite
cohérente au niveau système, en fin d'intégration du MOSA. Cette
présentation décrira ses fonctions et donnera...
I will describe the L0-to-L2 demonstration pipeline developed in order to address the FMT task 4.5 activity of LISA. The main goal of this activity is to show that it is possible to build a complete data analysis pipeline capable of generating L1 and L2 products from L0.5 data. The L0.5 to L1 step mainly includes on-ground processing that performs noise reduction, calculates pseudo-range...
The astrophysical Stochastic gravitational-wave backgrounds (SGWB) results from the superposition of numerous individually unresolved gravitational-wave (GW) signals. In this talk, I will present different ways of modelling the populations of stellar-mass compact binary coalescence (CBC) that source this background. I will discuss the use of population synthesis models to estimate the expected...
