Dixième Assemblée Générale du GdR Ondes Gravitationnelles

Session

Working groups sessions

5 oct. 2026, 11:00

Présidents de session

Working groups sessions: Prédictions et suivi des signaux multi-messagers

• Olivier GODET (IRAP)
• Floriane Cangemi (UPC/APC)
• Marion Pillas (IAP)

Working groups sessions: Tests de la relativité générale et théories alternatives

• karim Noui (IJCLab, Paris Saclay University)
• Eugeny BABICHEV (IJCLab)

Working groups sessions: Étoiles à neutrons, supernovae et synthèse des éléments lourds

• Matteo Bugli (UniTo - CEA Saclay)
• Sebastien Guillot (IRAP)
• Anthea FANTINA (GANIL ({CNRS}UPR3266))

Working groups sessions: Formes d'onde

• Eric Gourgoulhon (LUTH, Observatoire de Paris)
• Guillaume Faye (Institut d'Astrophysique de Paris)
• Alexandre Le Tiec (Observatoire de Paris)

Working groups sessions: Développement des détecteurs

• Angélique Lartaux (IJCLab)
• Eleonora POLINI (CNRS / OCA / ARTEMIS)
• Michal Was (LAPP/CNRS)

Working groups sessions: Méthodes d'analyse des données

• Yves Lemiere (LPCCaen, ENSICAEN, Unuiversité de Caen, CNRS/IN2P3, Caen, France)
• Florian Aubin (IPHC)
• Alba ROMERO RODRIGUEZ (Laboratoire D'Annecy de Physique de Particules (LAPP))

Working groups sessions: Cosmologie et Population des sources

• Michele Mancarella (Aix-Marseille Université)
• Giulia Cusin (IAP)
• Irina Dvorkin (Institut d'Astrophysique de Paris)
• Astrid Lamberts (Observatoire de la Côte d'Azur)
• Aurélien Chalumeau (LPC2E/OSUC)
• Tania Regimbau (LAPP)

12. Constraining the search for gravitational waves from binary neutron star mergers with kilonovae observations

Noah Jamsin (IJCLAB and IAP)

05/10/2026 11:00

Preferably a presentation, otherwise poster

The joint observation of gravitational waves (GWs) from a binary neutron star (BNS) merger (GW170817), together with a short Gamma-Ray Burst (GRB 170817A) and a kilonova (AT2017gfo), marked the birth of multimessenger astronomy with GWs, and clearly demonstrated the huge informative power of multimessenger observations. In the future more BNS merger and kilonova detections are expected, thanks...

22. Search for joint sources of neutrinos and gravitational waves with ANTARES and KM3NeT

Mathieu Lamoureux (APC)

05/10/2026 11:15

Astrophysical neutrinos are expected to be produced during transient phenomena that also produce gravitational waves, such as compact binary coalescences, in particular those involving neutron stars, or core-collapse supernovae. Gravitational waves are routinely detected by the LIGO-Virgo-KAGRA interferometers, while the ANTARES and KM3NeT deep-sea neutrino telescopes are sensitive to neutrino...

23. Memory effect from neutron star merger counterparts

Thomas Brabant (University of Liege)

05/10/2026 11:30

The gravitational-wave (GW) memory effect is a prediction of general relativity, characterized by a permanent change in spacetime geometry. Although it has not yet been observed, next-generation detectors such as the Einstein Telescope (ET) and the Laser Interferometer Space Antenna (LISA) are expected to provide the sensitivity required for its first detection. GW memory comprises two...

6. Catching non-linear memory effect with LISA & PTA

Adrien Cogez (CEA/IRFU/DPhP)

05/10/2026 14:00

Presentation

The gravitational memory effect is an unobserved prediction of general relativity, which states that gravitational waves can leave a permanent strain in spacetime. We investigated the prospects for detecting this memory effect with LISA from a massive black hole binary merger. Using Bayesian analysis, we assessed the conditions under which the memory signal can be confidently identified in...

18. New Aspects of spontaneous scalarization of black holes beyond General relativity

ZAKARIA BELKHADRIA (IP2I, Université Claude Bernard Lyon 1)

05/10/2026 14:15

Presentation

Spontaneous scalarization is a mechanism that allows black holes to develop a non-trivial profile of a scalar field “scalar hair” because of tachyonic instabilities, enabling tests of gravity beyond General Relativity. Motivated by stability and threshold issues in Gauss-Bonnet scalarization, we propose a new model characterized by two nonminimal couplings of the scalar field to both...

13. Radial Perturbations of Black Holes in DHOST Theories

Simon Iteanu (IJClab)

05/10/2026 14:30

Presentation

We study the gravitational waves of exotic Black Holes in modified theories of gravity (scalar tensor theories). We show that, in contrast with GR where radial perturbations are absent as a consequence of Birkhoff’s theorem, radial perturbations propagate a degree of freedom (DOF). This DOF combines both scalar and metric perturbations. We describe its propagation under the form of a...

24. Discussion du GT - Étoiles à neutrons, supernovae et synthèse des éléments lourds

Anthea FANTINA (GANIL ({CNRS}UPR3266)), Matteo Bugli (UniTo - CEA Saclay), Sebastien Guillot (IRAP)

05/10/2026 14:45

19. Impact of the equation of state on the evolution of rapidly rotating core-collapse supernovae

Dr Marco Cusinato (CEA-Saclay)

05/10/2026 15:05

Presentation

The evolution of core-collapse supernovae (CCSNe) involves the formation and evolution of a proto-neutron star (PNS), whose structure and dynamics are strongly governed by the nuclear equation of state (EOS). In rapidly rotating CCSNe, the EOS plays a key role in setting the conditions for the onset and evolution of non-axisymmetric instabilities.

We present three-dimensional...

5. Logarithmic divergence of the fluxes at the light ring for unstable circular orbits

David Trestini (University of Southampton)

05/10/2026 16:20

Presentation

At first self-force order, we consider the energy flux emitted by a particle orbiting a Schwarzschild black hole on an unstable circular orbit just outside the light ring. Both the flux to infinity and the flux down the horizon diverge as the orbit approaches the light ring, growing like the inverse of the distance to it, times a logarithm of that distance. This logarithmic divergence arises...

8. Radiation reaction in massless scalar-tensor theories to third post-Newtonian order

Eve Dones (IBS CTPU-CGA)

05/10/2026 16:32

Presentation

With the advent of third-generation gravitational-wave detectors, it has become crucial to extend analytical frameworks used to model waveforms from compact binary systems to alternative theories of gravity. In this talk, I will present recent results on radiation-reaction effects in a large class of scalar–tensor theories. Using the post-Newtonian multipolar post-Minkowskian (PN–MPM)...

1. Next-to-next-to-leading gravitational radiation-reaction corrections to quasi-elliptic and quasi-hyperbolic compact binary orbits

Emeric Seraille (LPENS)

05/10/2026 16:44

Presentation

Compact binaries are the primary sources of gravitational waves, and an accurate description of their dynamics is essential for constructing waveform templates for future gravitational-wave detectors. Recently, the gravitational radiation-reaction force for non-spinning compact binaries on generic orbits has been derived in harmonic coordinates at the fourth-and-a-half post-Newtonian (4.5PN)...

20. Charges aspects of BMS symmetries as opposed to a stress-energy tensor

Pierre Piovesan (CPT, Aix-Marseille Université)

05/10/2026 16:56

Presentation

The BMS group is the symmetry group at infinity of asymptotically flat spacetimes. In the presence of gravitationnal radiation, the associated Noether currents at null infinity are linked through flux-balance laws to variations of global quantities of the system, such as energy and angular momentum. I will present how, using the Noether currents fixed through a specific Wald-Zoupas...

9. Probing gravitational waves using the orbital dynamics of binary systems

Aurelien Hees (LTE - Observatoire de Paris)

06/10/2026 09:00

Preferably a presentation, otherwise poster

The internal dynamics of a binary system can be affected by the passage of gravitational waves (GWs). This effect is significantly enhanced when the GW frequency is in resonance with the orbital frequency of the binary system. Recently, this phenomenon has been proposed as a novel approach to detecting GWs in the largely unexplored microhertz frequency band, using precise measurements of the...

15. A landscape of possible higher-resolution mHz gravitational-wave missions

John Baker (L2I Toulouse, CNRS/IN2P3, Université de Toulouse)

06/10/2026 09:20

As we prepare for LISA to open observations in the mHz gravitational wave observational band in the next decade, it is also time to begin considering what could come next? One goal for a future mHz-band observatory, or a network of observatories, would be to enhance the ability to localize sources. We discuss possible design strategies for architectures of future LISA-like missions to improve...

25. Les défis pour LVK et ET

Dr Tania Regimbau ({CNRS}UMR5814)

06/10/2026 11:05

26. Les défis pour LISA et PTA

Stanislav BABAK (APC)

06/10/2026 11:25

21. Separating the GW background components with LISA through anisotropies and time-frequency techniques

Giorgio Mentasti (APC Paris)

06/10/2026 11:45

LISA will observe a superposition of astrophysical and cosmological stochastic backgrounds, whose disentanglement represents a major challenge for the data analysis. The talk is meant to give an overview on the ongoing research of GW background searches with LISA, and on how anisotropies can help in that direction. I then discuss what angular information adds to component separation, including...

10. Tfwaves: a time-frequency approach to long-lived LISA signals — from EMRIs to stellar-mass black hole binaries

Saptarshi GHOSH (Astroparticule et Cosmologie, Université Paris Cité)

06/10/2026 11:55

Preferably a presentation, otherwise poster

We present tfwaves, a Python package that represents long-lived gravitational-wave signals directly in the time-frequency domain. From the amplitude and phase of a time-domain waveform, it computes an analytical approximation of the Short-Time Fourier Transform, together with an approximate LISA response. The resulting representation is sparse: each harmonic occupies only a few frequency bins...

7. A weakly modelled view of the joint compact-binary mass plane: population structure and spectral-siren cosmology

Viola De Renzis (University of Milano-Bicocca)

06/10/2026 14:50

Preferably a presentation, otherwise poster

In this contribution, I will present a novel approach for reconstructing the compact-binary mass spectrum and exploiting its population features for gravitational-wave cosmology. We infer the population in the joint source-frame component-mass plane using a flexible mixture model, and introduce a model-independent procedure to identify structures directly from the reconstructed density and...

3. Probing Cosmology with Gravitational-Wave Dark Sirens using Euclid Galaxy Catalogs

Sarah Ferraiuolo (CPPM at Aix-Marseille University (AMU) & Università di Roma, La Sapienza)

06/10/2026 15:05

Presentation

We investigate the use of Euclid galaxy catalogs for gravitational-wave dark-siren cosmology using the GWTC-5 sample. We develop a framework to characterize the Euclid galaxy population, including photometric selection effects, catalog completeness, and the galaxy luminosity function through empirical Schechter fits. These ingredients are used to construct line-of-sight galaxy redshift priors...

11. Latest LIGO-Virgo-KAGRA cosmological results from the Gravitational Wave Transient Catalogue 5.0.

Maxime Bloch (Subatech (UMR 6457))

06/10/2026 15:25

Presentation

Authors

Maxime Bloch bloch@subatech.in2p3.fr (Subatech (UMR 6457)) for the LVK Collaboration

Abstract

This work presents the gravitational-wave (GW) measurement of the Hubble constant (H0) using the detections from the fifth observing GW Transient Catalog (GWTC-5.0) of the LIGO-Virgo-KAGRA Collaboration (LVK). Using the combined information from the luminosity distance of the...

16. Dark Sirens as Probes of Compact-Binary Host Galaxies

Michele Mancarella (Aix-Marseille Université)

06/10/2026 15:40

Presentation

Gravitational-wave (GW) dark sirens statistically associate GW luminosity-distance measurements with galaxies consistent with the source localization. This association contains astrophysical information about how compact binaries populate galaxies and the likely hosts of individual events. To date, however, dark-siren analyses have focused primarily on cosmology, fixing the galaxy–merger...