1st BiCoQ Conference: from gravity to particles

Session

Topical Session 4 - GW

17 Jun 2026, 11:30

49. Pinpointing PTA Single Sources: Sequential SBI for Sky Localization

Ludovica Carbone (University of Milano-Bicocca)

17/06/2026, 11:30

Oral contribution

Accurate localisation of continuous gravitational waves (CGWs) from supermassive black hole binaries (SMBHBs) remains one of the key challenges in Pulsar Timing Array (PTA) data analysis. Traditional searches based on the $\mathcal{F}_e$ statistic provide a robust analytic framework, but the resulting sky maps are strongly affected by the PTA antenna pattern, which redistributes signal power...

61. Investigating the role of inter-source correlations in LISA data analysis

Rachele Rosso (University of Trento - University of Pisa)

17/06/2026, 11:50

Oral contribution

We investigate how overlapping signals from massive black hole binaries can bias gravitational wave measurements in future missions like LISA. We demonstrate that ignoring these inter-source correlations during individual analysis leads to systematic errors in the recovered physical parameters. These biases are a fundamental risk for any frequency-domain data-reduction technique that disrupts...

43. Gravitational wave astronomy without waveform approximants

Matteo Boschini (University of Milano-Bicocca)

17/06/2026, 12:10

Oral contribution

Gravitational wave astronomy relies on waveform approximants for both detection and parameter estimation. However, these models inherit uncertainties that grow increasingly relevant as detectors sensitivity improves. Notably, GW231123 revealed discrepancies between different waveform models. In this work we explore the possibility to perform parameter estimation directly from numerical...

63. Gravitational waves lensing, a new opportunity for investigating gravity and dark matter ?

Martin Pijnenburg

17/06/2026, 14:00

Oral contribution

Gravitational lensing, i.e. the deflection of propagating signals by spacetime curvature is one key prediction of General Relativity. Besides this intrinsic interest as a fundamental prediction, this effect has become one crucial probe used by the cosmology community to identify and map dark matter.
Relying on the idea that the propagation of both electromagnetic and gravitational waves (GW)...

45. Eccentricity in binary black hole event from the third gravitational wave transient catalog

Matilde Garcia (Universitá degli Studi Milano Bicocca)

17/06/2026, 14:20

Oral contribution

The first detection of gravitational waves in 2015 opened a new window into the universe, offering a unique probe of the properties and evolution of binaries of compact objects (black holes and neutron starts). There are several proposed channels through which these binaries form and merge, and one of the key challenges in gravitational wave astrophysics it to unambiguously pinpoint them...

16. Measuring binary black hole time-delay distribution with GWxLSS

Nicola Bellomo (University of Padova)

17/06/2026, 14:40

Oral contribution

Gravitational wave observatories offers a unique view into the physics of compact object binary systems. However, the richness of astrophysical models is partially lost due to our ability of measuring a limited number of parameters from individual GW events, thus limiting our ability to break degeneracies between different models. It then becomes crucial to find alternatives ways to extract...

30. Tracing formation channels with spin–orbit misalignment in black-hole binaries

Sofia Dossena

17/06/2026, 15:00

Oral contribution

Understanding the formation channels of black hole binaries remains an open problem in gravitational-wave astronomy, made increasingly compelling by the growing catalog of detections from LIGO-Virgo-KAGRA. In this talk, I present a comparison between binaries formed through isolated (field) binary evolution and those assembled dynamically in dense environments, with particular focus on...

46. Tackling labelling-related uncertainties in the mass and spin distributions of compact objects in binary systems observed via Gravitational Waves

Giulia Cuomo (University of Milano - Bicocca)

17/06/2026, 15:20

Oral contribution

All Gravitational Wave signals detected so far were generated by the coalescence of black holes and/or neutron stars in binary systems. Correctly identifying the primary and secondary objects within said systems is crucial to obtain unbiased astrophysical information regarding their masses and spins; as of now, labels are assigned on a mass basis: the "primary" label is given to the more...

62. samsara: A Continuous-Time Markov Chain Monte Carlo Sampler for Trans-Dimensional Bayesian Analysis

Gabriele Astorino (University of Pisa)

17/06/2026, 15:40

Oral contribution

Trans-dimensional Bayesian analysis requires determining the posterior distribution when the number of parameters is not fixed. In this talk, I will present an alternative approach to Reversible Jump Markov Chain Monte Carlo and Simulation-Based Inference. Our method relies on the evolution of the parameter space through birth-death and mutation processes in a continuous-time framework. More...

58. Probing Supermassive Black Hole Mergers with Pulsar Timing Arrays

Hippolyte Quelquejay (Università degli Studi di Milano-Bicocca)

17/06/2026, 16:30

Oral contribution

By monitoring the times of arrival of radio pulses from millisecond pulsars, Pulsar Timing Arrays (PTAs) serve as unique gravitational wave (GW) laboratories in the nanohertz band.
To date, the primary astrophysical sources of GWs targeted in this frequency range have been inspiraling supermassive black hole binaries (SMBHBs) on circular or eccentric orbits.
In this work, we demonstrate...

52. Modeling the nHz gravitational wave background with t-process

Beatrice Eleonora Moreschi (University of Milano-Bicocca)

17/06/2026, 16:50

Oral contribution

Unveiling the nature of the nanoHz gravitational wave signal reported by Pulsar Timing Array collaborations is the next goal of low-frequency GW astronomy. The signal likely originates from the incoherent superposition of GWs emitted by a population of supermassive black hole binaries (SMBHBs). The discrete nature of the population, environmental effects and eccentricity are expected to...

14. Spin-2 Boson Stars

Andrea Gobbo (Università degli Studi di Milano-Bicocca)

17/06/2026, 17:10

Oral contribution

The relevance of compact objects to both astrophysics and theoretical physics is well-established, as the extreme compactness of these systems provide an optimal environment to probe the strong-field gravity regimes. Within this framework, boson stars are considered to be viable models for ultralight dark matter, as well as black hole mimickers. While scalar boson stars offer simple,...

47. Probing astrophysical environment of stellar mass black holes through the LISA stochastic signal

Rohit Subbarayan Chandramouli (SISSA)

18/06/2026, 14:00

Oral contribution

The LISA stochastic signal from stellar mass black holes may be detectable. In this talk, given such a detection, I will describe how the presence of an astrophysical environment can be inferred from the stochastic signal. Additionally, I will discuss how eccentricity affects the spectrum and can be used as an indirect probe of the astrophysical formation of such binaries. Finally, I will...

44. Photometric identification and spectroscopic confirmation of massive black hole binaries

Lorenzo Bertassi (Università degli Studi di Milano-Bicocca)

18/06/2026, 14:20

Oral contribution

Massive black hole binaries (MBHBs) are expected to be among the loudest gravitational wave sources to be detected by pulsar timing arrays and space-borne interferometers. If accreting, MBHBs at sub-parsec separations can be identified through periodic variability in their light curves. Current periodicity detection methods are largely optimised for quasi-sinusoidal signals, whereas the...

65. Massive Black Holes formation and evolution in cosmological environments

Mr Daniele Spinoso (Dipartimento di Fisica "G. Occhialini", Università degli Studi di Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, 20126, Milano (IT))

18/06/2026, 14:40

Oral contribution

Recent observations of high-redshift luminous QSOs and faint AGN candidates, as well as the upcoming space-based gravitational wave experiments, motivate the development of detailed theoretical models which focus on the formation and evolution of massive black holes (MBHs). This talk will present recent results obtained with the L-GalaxiesBH (LGBH) semi-analytic model about the formation,...

48. Towards a comprehensive description of black hole binary inspiral from Newtonian to relativistic scales

Alessandro Lupi (Como Lake Centre for Astrophysics, University of Insubria)

18/06/2026, 15:00

Oral contribution

The massive black hole binary (MBHB) path from formation on galactic scales down to their coalescence is extremely complex, and still poorly constrained, due to the huge dynamical range involved and the variety of physical processes at play on different scales. With the approval of the LISA mission, we are entering now a new era for MBHB astronomy, that requires a detailed theoretical...

7. Eccentricity distribution of extreme mass ratio inspirals

Davide Mancieri (University of Trento / University of Milano-Bicocca)

18/06/2026, 15:20

Oral contribution

We present realistic eccentricity distributions for extreme mass ratio inspirals (EMRIs) forming via the two-body relaxation channel in nuclear star clusters, tracking their evolution up to the final plunge onto the central Schwarzschild massive black hole (MBH). We find that EMRIs can retain significant eccentricities at plunge, with a distribution peaking at $e_\mathrm{pl} \approx0.2$, and a...

33. Warped accretion discs and black-hole spins in gravitational-wave astronomy

Lisa Merlo (University of Milano-Bicocca)

18/06/2026, 15:40

Oral contribution

Spin configuration of supermassive black-hole binaries affect gravitational waves at post-Newtonian level, making it observable by the future LISA space mission. Spin alignment is of significant relevance not only for black-hole recoils, whose kick magnitude increases with binary misalignment and can be greater than galaxies' escape velocity, but also as a possible discriminant between...

21. A gravitational-wave event is exceptional only compared to something else

Davide Gerosa (University of Milano-Bicocca)

Oral contribution

In gravitational-wave astronomy, as in other scientific disciplines, "exceptional" sources attract considerable interest because they challenge our current understanding of the underlying (astro)physical processes. Crucially, "exceptionality" is defined only relative to the rest of the detected population. For instance, among all gravitational-wave events detected so far, GW231123 is the...