Gravitation

Detecting low-frequency gravitational waves

The first detection of gravitational waves (GWs) from coalescing binary black holes by the
LIGO-VIRGO scientific collaboration has opened a new era in astrophysics: gravitational wave
astronomy. The ground based detectors operate at high frequencies (above 10 Hz), and there are
two major world-wide efforts to detect GW st low frequency. The GWs in the nano-Hz band will
be detected with the Pulsar Timing Array (PTA).
Here we use nature-provided detector: we monitor ultra-stable millisecond pulsars which work

Simulations and associated data analysis for realistic LISA configuration / Simulations et analyses de données pour une configuration réaliste de LISA

The Laser Interferometer Space Antenna (LISA) is a large mission of the European Space Agency. It will address the scientific theme of "The Gravitational Universe" by observing gravitational waves sources emitting between 0.02 milliHertz and 1 Hertz. LISA is formed by tree spacecrafts on heliocentric orbits exchanging laser beams over 2.5 millions kilometers in order to measure the deformation of spacetime of few pico-meters due to gravitational waves.

2-years post-doctoral position on experimental gravitational-wave astronomy

The first LIGO-Virgo gravitational-wave detections had dramatic consequences for astrophysics, cosmology and tests of general relativity. In order to increase the volume of the observed sky and then the signal-to-noise ratio of the signals detected, an increase of the Virgo sensitivity is crucial. In the next years, periods of data takings alternated with periods of detector’s upgrades will be performed for both Virgo and LIGO.

Increasing the science reach of the LIGO-Virgo gravitational-wave detector network by improving the sensitivity and the quality of the Virgo data.

In August 2017 Virgo made its first gravitational-wave detections together with LIGO. The detection of the gravitational-waves emitted by the binary black-hole coalescence (GW170814) and the binary neutron star coalescence (GW170817, with its electromagnetic counterparts GRB170817a and AT2017gfo) had dramatic consequences for astrophysics, cosmology and tests of general relativity.

The gravitational universe: searching for progenitors of gravitational waves

Context: The discovery, by the LIGO-Virgo collaboration on Sept. 14th 2015, of gravitational waves (GW) from the merger of two stellar-mass black holes, applauded by the whole scientific community, was unexpected in terms of astrophysical sources: two such heavy stellar-mass black holes (~30 solar masses) had never been seen before, although now, they likely constitute the tip of the iceberg. From this detection, several questions immediately arose: how can such black holes form, and how many are there in our local Universe and beyond?

Bayesian population study and testing General Relativity with gravitational waves from coalescing binaries

The gravitational wave detectors run by LIGO/VIRGO collaboration have detected 4 gravitational wave (GW) signals from merging BHs. The data from the last (second) observational run are still being analyzed
and more detections might be announced shortly. The ground-based detectors are now offline for the further upgrade, and we expect a significant increase in the detection rate in the next observational period. In addition, the preparations for the space-based GW observatory, LISA, have already started. The LISA data will

Gravitational wave confusion problem across frequency bands

LIGO/VIRGO collaboration has announced 4 confirmed detection of gravitational wave (GW) signals
from the merging binary black holes. This opens a new window in the astronomy: gravitational wave astrophysics.
There are three major efforts to search for GWs: LIGO-VIRGO detectors operating in the frequency range
between few Hz and kHz, LISA - space based detector which will be launched in 2034 and is sensitive
in the milli-Hertz band, PTA (Pulsar Timing Array) - uses the monitoring of millisecond (stable) pulsars
to detect GWs in the nano-Hertz band.

Resolving relativistic compact binaries using gravitational waves

In late 2015, the Advanced LIGO-Virgo collaboration announced the first detections of a number of binary black holes using gravitational waves.  These detections have opened up the new field of gravitational wave astronomy.  In the next few years, there are a number of planned science runs that should provide many more detections.  An important aspect of the detection process is the fast and accurate estimation of the astrophysical parameters of the system.  We currently collaborate with 83 telescopes, satellites and neutrino detectors around the world.  To search for an electromagnetic cou

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