LISA est une constellation de 3 satellites en orbite héliocentrique, située à environ 50 millions de kilomètres de la Terre. Les satellites formeront un triangle équilatéral, dont les bras mesurent 2,5 millions de kilomètres. Ainsi ils formeront un interféromètre optique orienté à 60° du plan de l’orbite terrestre.
Les charges utiles seront reliées 2 à 2 par des signaux lasers synchronisés,...
This talk will provide an overview of the LISA Distributed Data Process Center (DDPC) and will present the current status of its implementation.
The LISA data stream will have interruptions, both scheduled and un-scheduled, due to repointing of the antennae or other instrumental disturbances. These data gaps must be taken into account in our data analysis algorithms. In this talk, we discuss a direct method that can account exactly for data gaps in LISA data, both in time and Fourier domain, although computationally expensive and...
The immense scientific potential of LISA hinges on solving an unprecedented data analysis challenge: the Global Fit problem. This involves the simultaneous inference of numerous overlapping signals and instrument noise, framed in a high-dimensional Bayesian setting.
Current approaches rely on computationally intensive Markov chain Monte Carlo (MCMC) techniques with block Gibbs sampling...
The LISA mission is a space-based interferometer designed to detect gravitational waves at frequencies on the order of millihertz. LISA will detect numerous types of sources, such as compact binary systems: EMRIs, MBHBs, and GBs.
Data processing is a major challenge for this mission, as several thousand sources will need to be analyzed simultaneously due to their overlap in both the time...
LISA observations of Massive Black Hole Binaries (MBHBs) will provide high signal-to-noise ratio (SNR) data, ideal for testing General Relativity (GR) in the strong field regime. MBHBs with masses between $10^4$ and $10^7M_{\odot}$ produce inspiral signals in LISA's frequency band, well-modeled by the Post Newtonian (PN) approach, followed by loud merger-ringdown signals. We present a...
Ground-based gravitational wave detectors have observed dozens of binary black holes. Some of them may have formed in dynamic environments, such as globular clusters or active galactic nuclei (AGN) disks. In this case, third-body interactions with (super-)massive, and possibly intermediate mass BHs will imprint clear signatures on observed GW signals due in particular to the gravitational pull...
Features in the black hole population provide crucial information for measuring cosmology using only gravity. If this method is used for current gravitational wave observations, it has significant potential for applications to LISA sources. I present the first realistic population and spectral siren analysis using state-of-the-art catalogs of massive black hole mergers to infer both population...
Modern cosmology is confronted with a persistent tension over the value of the Hubble constant $H_0$, between local measurements (e.g. by SH0ES) and estimates from the cosmic microwave background (by Planck). Gravitational waves (GWs) offer a new way of assessing the expansion of the Universe, in particular by using dark sirens, which are gravitational sources with no electromagnetic...
Gravitational waves (GWs) can be used to measure $H_0$ and help solve the Hubble tension since they provide us with an independent estimates of a source's luminosity distance and redshift. Future-generation detectors, such as LISA or ET, will contribute to this field both by improving the measurement of resolved events, and by providing measurement of the stochastic gravitational waves...
