The Einstein Telescope (ET), a third-generation gravitational-wave (GW) observatory, will extend the sensitivity and bandwidth of current detectors, enabling observations from ~1 Hz and vastly increasing the detection rate of compact binary coalescences (CBCs). This leap in capability introduces new data analysis challenges, including increased rates of overlapping signals that can generate...
The sensitivity of Gravitational Waves (GW) interferometers is limited by noise. Non-Gaussian transient noise artifacts, also known as glitches, are particularly challenging due to their similarity with astrophysical signals in the time and frequency domains; for this reason noise reduction and subtraction is one of the most important and challenging activities in GW research. Within the...
Gravitational wave data are often contaminated by transient noise artifacts, called "glitches", which can mimic astrophysical signals and interfere with their detection. When represented in the time-frequency domain, glitches show peculiar morphologies, which allow their categorization into distinct families. As it is expected that glitches which share a similar morphology also share the same...
This work explores feature selection for glitch classification in gravitational wave detectors, where transient noise events are grouped by their time-frequency morphology. Gravity Spy is a citizen-science project that provides a standard dataset built from four Q-transform views of glitches. Follow-up studies introduced attention-based multi-view models, transfer learning, and examined the...
The speed-up of parameter estimation is an active field of research in gravitational-wave data analysis. In this paper we present GP12, a deep-learning method that merges residual networks and normalising flows into a general-purpose, image-based estimator of binary black hole (BBH) parameters. Building on our early work we map BBH spectrograms from the Advanced LIGO and Advanced Virgo...
Source inference for deterministic gravitational waves is a computationally demanding task in LISA. In a novel approach, we investigate the capability of an active-learning Gaussian Processes-based framework to learn the posterior for source parameters, using a very small number of likelihood evaluations, and without the need for pretraining. We benchmark our method against a cutting-edge...
We develop a framework for accelerated parameter estimation for lensed gravitational waves in the wave-optics regime. To model these effects, we evaluate the amplification factor using GLoW, an accurate code that computes the frequency-dependent amplification factor for generic lens models and arbitrary impact parameters depending on the lens configuration. To extract physical parameters from...
Wave-optics phenomena in gravitational lensing occur when the signal's wavelength is commensurate to the gravitational radius of the lens. Although potentially detectable in lensed gravitational waves, fast radio bursts and pulsars, accurate numerical predictions are challenging to compute. In this talk I will present recent advances on numerical methods to tackle this problem and their...
In the Standard Model (SM), the electroweak phase transition – which marked the breaking of the $SU(2) \otimes U(1)$ symmetry through the Higgs mechanism – is predicted to have been a crossover. Several extensions of the SM, however, can realize it as a first-order phase transition (FOPT), which might lead to successful electroweak baryogenesis in the early universe.
A FOPT proceeds through...
Self-interacting dark matter (SIDM) model with a density spike can potentially solve the final-parsec problem. Hence, we probe this model using the gravitational wave background data from pulsar timing array. We found that our results for the SIDM model parameters are consistent with the existing literature.
We present a study of scattered light noise in ground-based gravitational-wave detectors, based on advanced simulations for the Einstein Telescope (ET) and Virgo. Stray light mitigation remains a critical challenge for current interferometers, as the residual light can couple into the main beam and limit the sensitivity. For ET, we present updated noise estimations for both the high- and...
Accurate interferometric simulations are essential to understand and optimize the performance of current gravitational wave (GW) detectors, as well as to design next-generation observatories. Sim- ulations play a crucial role in improving detector sensitivity, testing new control strategies and devel- oping advanced noise mitigation techniques. Particularly as the global GW network sensitivity...
Accurate modeling of gravitational waves from precessing binary systems is essential for improving signal detection and parameter estimation in current and future detectors. Hybrid waveforms, which stitch together gravitational wave signals from different modeling approaches, provide a way to generate complete inspiral-merger-ringdown signals. While hybridization is well-established for...
The modeling of spin-precession and orbital eccentricity in gravitational-wave (GW) signals is crucial for understanding the astrophysical formation of compact binaries and ensuring that GW detector data is explored fully and without biases. However, describing these effects accurately and efficiently remains a challenge. In this talk, I will present pyEFPE, a frequency-domain post-Newtonian...
The first three observing runs of the LIGO-Virgo-KAGRA (LVK) Collaboration have led to the detection of over 90 gravitational wave (GW) events from compact object binaries, but understanding their formation channels still remains an open question in GW astrophysics. While most inspiraling binaries detected by ground-based detectors likely form through isolated binary evolution and are expected...
A non-negligible population of binary black holes (BBHs) forming dynamically in active astrophysical environments is predicted to radiate graviational waves (GWs)
in the frequency band of ground-based LIGO, Virgo and KAGRA (LVK) GW detectors. Thus, strong evidence for orbital eccentricity in GW detections will play a pivotal role in unveiling the astrophysical origins of BBH mergers. Despite...
We address the challenge to evaluate the response of the Laser Interferometer Space Antenna (LISA) in an accurate and computationally efficient way.
Without approximations, the full LISA response is computationally expensive and traditional approaches, such as the long-wavelength approximation, accelerate the response calculation at the cost of reducing accuracy at high frequencies. Here we...
Gravitational waves from binary black hole mergers encode astrophysical information in multiple spherical harmonic modes. While dominant and subdominant modes have been extensively studied, the (l=2, m=0) mode has only recently been incorporated into waveform models.
We present a phenomenological waveform model for the (2,0) mode, capturing its two components: the non-oscillatory displacement...
We present IMRPhenomXHM_NSBH, a new phenomenological model for graviational-wave (GW) emission from neutron star–black hole (NSBH) coalescences. This model features a newly developed numerical relativity (NR)-calibrated amplitude prescription incorporating tidal contributions up to 7.5PN order, a phasing model tuned to NR simulations incorporating dynamical tidal effects (NRTidalv3), and the...
Since the first detection of a binary neutron star system, GW170817, the number of compact binary systems involving neutron stars observed by the LVK network has continued to grow. The tidal deformability of neutron stars influences the gravitational waves emitted during inspiral phase, making these effects observable. Consequently, waveform models used to analyze such signals must incorporate...
One of the longest-standing science targets of gravitational-wave detectors are spinning deformed neutron stars. While exceedingly weak and hence still eluding detection, "continuous waves" from such individual objects will bring a new regime of gravitational astrophysics where we can keep observing the same source over and over and perform rich multi-messenger studies. They promise an...
Neutron stars are expected to produce continuous gravitational waves arising due to precession and, crucially, deformations in the crust, also called mountains. The microscopical resistance to breaking used in ellipticity calculations is obtained from Molecular Dynamics simulations. In this talk I will show our results from our simulations, that incorporate finite size and magnetic fields. I...
While standard analyses of black-hole mergers assume these happen in vacuum, it is expected that these will happen in dense environments. This is particularly true for mergers involving component black holes populating the so-called pair-instability supernova gap, which should form hierarchically as the result of a previous merger in an environment dense enough to retain the remnant black...
Black holes and neutron stars are the leading candidates for the sources of currently observed gravitational waves. However, exotic compact objects have been proposed as potential alternatives, capable of mimicking the gravitational-wave signatures of these standard sources. Among them, Proca stars—Bose-Einstein condensates of complex vector ultralight bosons—have attracted...
Binary supermassive black holes are expected to form and merge at galactic centers. Their dynamics encode information on their formation and environments, and can be observed by low frequency gravitational-wave detectors, potentially offering a multi-messenger source. Despite this interest, no close-by (sub parsec) binaries have been confidently identified yet.
I will describe a new method...
The yet-to-be-detected gravitational wave signal from core-collapse supernovae is expected to be dominated by oscillation modes of the newly born proto-neutron star (PNS). I am going to present a new general relativistic framework for computing the oscillation modes of a PNS, including, for the first time, an accretion flow and a surrounding stalled accretion shock. The oscillations can be...
The accurate modelling of neutron star oscillations is essential as we prepare for the next generation of gravitational-wave detectors, which will be able to probe the rich astrophysical content of post-merger signals. In this talk, I will present recent updates to ROXAS, a spectral code to numerically simulate the dynamical evolution of perturbed rotating neutron stars. ROXAS uses a...
A deep correspondence exists between the quasi-normal modes (QNMs) of ultra-compact objects and their observable gravitational lensing features, such as photon rings and shadows. In the era of multi-messenger astrophysics, a comprehensive understanding of this relation is crucial for extracting fundamental spacetime properties. We present how we can use this correspondence to test beyond...
Blazars show variability across the entire electromagnetic spectrum and over a wide range of timescales. In some cases, characteristic emission patterns have been observed, such as the multi-year modulation detected in PG 1553+113. Quasi-periodic oscillations (QPOs) can arise from various astrophysical mechanisms, including jet precession, accretion disk instabilities, and supermassive binary...
Pulsar Timing Array (PTA) observations provide strong evidence for a stochastic gravitational wave background (SGWB), potentially originating from astrophysical sources or early universe phenomena. If the SGWB is cosmological, our relative motion with respect to the SGWB rest frame induces a kinematic anisotropy, which could dominate over intrinsic anisotropies, similar to the cosmic microwave...
