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D. Verkindt

Publications and source records attributed to D. Verkindt.

3 recordsLinked to original sources

The Advanced Virgo Photon Calibrators

As the sensitivities of LIGO, Virgo and KAGRA detectors improve, calibration of the interferometers output is becoming more and more important and may impact scientific results. For the observing run O3, Virgo used for the first time photon calibrators (PCal) to calibrate the interferometer, using radiation pressure of a modulated auxiliary laser beam impinging on the Advanced Virgo end mirrors. Those optical devices, also used in LIGO, are now the calibration reference for the global gravitational wave detectors network. The intercalibration of LIGO and Virgo PCals, based on the same absolute reference called the Gold Standard, has allowed to remove a systematic bias of 3.92% that would have been present in Virgo calibration using the PCal. The uncertainty budget on the PCal-induced displacement of the end mirrors (NE and WE) of Advanced Virgo has been estimated to be 1.36% for O3a and 1.40% on NE PCal (resp. 1.74% on WE PCal) for O3b. This uncertainty is the limiting one for the global calibration of Advanced Virgo. It is expected to be reduced below 1% for the next observing runs.

astro-ph.IM

First Tests of a Newtonian Calibrator on an Interferometric Gravitational Wave Detector

The ongoing improvements of the advanced gravitational wave (GW) detectors are setting challenging requirements on instrument calibration. We report tests of a calibration technique, based on the well-known gravitation force, which has been applied for the first time on a large interferometer. The results obtained with Advanced Virgo are in good agreement with the predictions and with the usual calibration method. This technique is expected to lead to accurate absolute calibration at the sub-percent level in the coming years, matching the needs of the blooming GW science.

gr-qc

Variable placement of templates technique in a 2D parameter space for binary inspiral searches

In the search for binary systems inspiral signal in interferometric gravitational waves detectors, one needs the generation and placement of a grid of templates. We present an original technique for the placement in the associated parameter space, that makes use of the variation of size of the isomatch ellipses in order to reduce the number of templates necessary to cover the parameter space. This technique avoids the potentially expensive computation of the metric at every point, at the cost of having a small number of ``holes'' in the coverage, representing a few percent of the surface of the parameter space, where the match is slightly lower than specified. A study of the covering efficiency, as well as a comparison with a very simple regular tiling using a single ellipse is made. Simulations show an improvement varying between 6% and 30% for the computing cost in this comparison.

gr-qc