S Babak | Searcharxiv

arXiv2026

Advanced Virgo during the LIGO-Virgo-KAGRA fourth observing run

From April 10, 2024 to November 18, 2025 Advanced Virgo participated in the fourth observing run of the network of gravitational-wave detectors, together with Advanced LIGO and KAGRA. For this observing run Advanced Virgo has completed its design optical configuration with the installation of a signal recycling mirror. In this paper we describe the challenges encountered in commissioning this optical configuration, alongside the other upgrades performed between the third and fourth observing run. The Virgo detector operated with a 68.9% duty cycle and with an angle-averaged median range to binary neutron star mergers of 53 Mpc.

gr-qc↗

arXiv2007

An overview of the second round of the Mock LISA Data Challenges

The Mock Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data-analysis tools and capabilities and of demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data. The first round of MLDCs has just been completed and the second-round data sets are being released shortly after this workshop. The second-round data sets contain radiation from an entire Galactic population of stellar-mass binary systems, from massive--black-hole binaries, and from extreme--mass-ratio inspirals. These data sets are designed to capture much of the complexity that is expected in the actual LISA data, and should provide a fairly realistic setting to test advanced data-analysis techniques, and in particular the global aspect of the analysis. Here we describe the second round of MLDCs and provide details about its implementation.

gr-qc↗