Population synthesis is a crucial tool for studying the predictions of binary evolution models on many astrophysical objects and transients of interest. In this study, we use the population synthesis code COMPAS to constrain the uncertain physics of binary mass transfer, using a locally complete sample of stripped-envelope supernovae. We argue that current evolutionary models are surprisingly...
Despite the increasing number of GW detections, the astrophysical origin of the Binary Black Hole (BBH) mergers detected by the LIGO and Virgo interferometers remains elusive. A promising formation channel for these BBHs is inside accretion discs around supermassive black holes, that power AGN. Investigating the spatial correlation between the positions of these potential host environments and...
Current parameter-estimation techniques for the coalescence of compact binaries assume just one event in the data stream. With the low detection rate of current interferometers, is has not been a problem so far, as overlapping signals are highly improbable. This will change with the next generation (3G) of detectors, like Cosmic Explorer and Einstein Telescope, with hundreds of overlaps per...
Orbital eccentricity is a crucial physical effect to unveil the origin of compact-object binaries detected by ground- and spaced-based gravitational-wave (GW) observatories. Here, we perform for the first time a Bayesian inference study of inspiral-merger-ringdown eccentric waveforms for binary black holes with non-precessing spins using two (instead of one) eccentric parameters: ...
The last phase of a black hole merger is accompanied by a train of damped gravitational radiation known as the ringdown. It can be described linearly at late times, as a sum of discrete modes: the quasi-normal modes (QNMs) of the final Kerr black hole. As a consequence of the black hole no-hair theorem, the QNM frequencies are fully determined by the mass and spin of this black hole. Measures...
The advent of gravitational-wave astronomy is now allowing for the study of compact binary merger demographics throughout the Universe. This information can be leveraged as tools for understanding massive stars, their environments, and their evolution. One active question is the nature of compact binary formation: the environmental and chemical conditions required for black hole birth and the...
The next generation of space- and ground-based facilities promise to reveal an entirely new picture of the gravitational wave sky: thousands of galactic and extragalactic binary signals, as well as stochastic gravitational wave backgrounds (SGWBs) of unresolved astrophysical and possibly cosmological signals. Here, I will focus on one particular analysis challenge: reconstructing an SGWB from...
Once a gravitational wave signal is detected, the measurement of its source parameters is important to achieve various scientific goals. This is done through Bayesian inference, where the analysis cost increases with the model complexity and the signal duration. For typical binary black hole signals with precession and higher-order modes, one has 15 model parameters. With standard methods,...
We know very little about the first few seconds of the universe, beyond the very successful Big Bang nucleosynthesis. In those first instants, First Order phase transitions in the early plasma could have taken place and reshape the content of the plasma and spacetime. For the computation of baryogenesis, gravitational waves, dark matter production or even possibly PBH production, the...
The current and upcoming generations of gravitational wave experiments represent an exciting step forward in terms of detector sensitivity and performance. Key upgrades at the LIGO, Virgo and KAGRA facilities will see the next observing run (O4) probe a spatial volume around four times larger than the previous run (O3), and design implementations for e.g. the Einstein Telescope, Cosmic...
A major science goal of gravitational-wave (GW) observations is to probe the nature of gravity and constrain modifications to General Relativity. An established class of modified gravity theories are scalar-tensor models, which introduce an extra scalar degree of freedom. This affects the internal structure of neutron stars (NSs), as well as their dynamics and GWs in binary systems, where...
The recent start of the fourth observing run of the LIGO-Virgo-KAGRA (LVK) collaboration has reopened the hunt for gravitational-wave (GW) signals, with one compact-binary-coalescence (CBC) signal expected to be observed every few days. Among the signals that could be detected for the first time there is the stochastic gravitational-wave background (SGWB) from the superposition of unresolvable...
Future detections of gravitational waves originating from binary neutron star mergers or core-collapse supernovae offer the potential to gain unprecedented insights into the structure of matter at densities far beyond those probed by Earth-based experiments. In order to be able to identify the correct equation of state of matter, a template bank of waveforms has to be generated by general...
Modelling the gravitational-wave (GW) emission of core-collapse supernovae is needed to, e.g., relate a detected GW to the properties of its source or test different models. To obtain such models, we will use the GRMHD code Gmunu to study the effect of different parameters of the collapsing star on the waveforms.
Astrometric surveys can be used to constrain the stochastic gravitational wave background (SGWB) at very low frequencies. The European Space Agency's (ESA) Gaia mission, launched in 2013 and with a recent data release (DR3) in 2022, shows great potential for this purpose. In this talk, I will present a recent work in which we used Gaia DR3 to set constraints on the SGWB amplitude. I will also...
The increasing number of GW detections paves the road towards pinning down the values of the most important cosmological parameters, enabling us to do precision cosmology. This approach requires the careful mitigation of various systematic effects, which become more and more important as the accuracy of our cosmological inference grows. In this talk, I will present the UpGLADE galaxy...
Dark siren measurement of Hubble constant is one of the most exciting results in the multimessenger astronomy. Currently, the uncertainty of this measurement is dominated by the unknown gravitational wave events population. However with more events and better sensitivity of detectors, the uncertainty will shrink, therefore it is important to study impact of uncertainties from different...
We propose a novel scheme how to obtain quantum back action evading measurement on a gravitational wave detector, by introducing negative radiation pressure coupling between the field and the end mirror. The scheme consists of replacing the end mirror with a double-faced one and adding another optical cavity next to it. The measurement is performed by sending a two-mode squeezed vacuum to both...
In the era of large scale galaxy surveys, significant effort has been put in constraining cosmological models with unprecedented precision. In this context, gravitational waves (GW) might play a pivotal role to improve our understanding of the Universe. In particular, the clustering of gravitational waves potentially allows to constrain perturbation growth, similarly to galaxy clustering. As...
In this poster I will present semi-analytic code designed to simulate modal propagation and coupling of Hermite-Gauss laser modes in and out of the Input and Output mode cleaner cavities that will be used on R&D and 3G detectors. Outputs from the code are graphical plots that serve as heuristic tools for narrowing down choices of cavity parameters (RoC, L, Finesse, internal angles etc.). The...
New challenges in gravitational-wave astrophysics impose increasing sensitivity of current interferometric detectors operating at room temperature as Advanced LIGO and Advanced Virgo. Limits at their most sensitive frequency region arise from the Brownian thermal noise of the highly-reflective coatings on the interferometer mirrors. Such coatings are composed of alternating layers of low- and...
Interferometric gravitational-wave detectors have opened a new window into the Universe, creating new opportunities in the branch of astrophysics. While current detectors allow for successful detections, there is a need to increase their sensitivity by trying to enlarge their frequency band to observe additional types of gravitational waves sources. Future cryogenic detectors such as the...
The forthcoming era of gravitational wave detectors, exemplified by the Einstein Telescope, demands unprecedented levels of sensitivity. Central to this
progress is the deployment of cryogenic low-frequency interferometers, hinging
on silicon as the mirror substrate material. A critical hurdle lies in mitigating
coating thermal noise, a main limiting factor to detector precision. This...
The discovery of gravitational waves paved the way for a new way of seeing the Universe, but above all, it paved the way for the development of new technologies.
Since the first gravitational-wave detection much progress has been made and the technology that allowed us to explore this new field has been renewed.
The cornerstone of this research remains the Michelson interferometer, whose...
A gravitational wave detector can measure small periodic distortions in spacetime known as gravitational waves. Improvement in the sensitivity of these detectors can help gain new insight into physics. These instruments require mirror coatings made of low and high refractive index layers with very low coating thermal noise. Future detectors, such as the Einstein Telescope, will operate at...
Over the past decades, observations have established a sample of more than 200 bright Active galactic nuclei (AGN), powered by accretion onto massive black holes, in the first billion years of the Universe. The James Webb Space Telescope has significantly revised this sample by yielding a sample of unexpectedly numerous and large black holes (up to a 100 million solar masses) within the first...
With the onset of next generation gravitational interferometers, we find ourselves in an era where we can peer into cosmic time and see the influence of mergers on the growth of supermassive black holes (SMBH). Here, we investigate properties of a cluster of intermediate-mass black holes surrounding a supermassive black hole. A model first proposed by Ebisuzaki et al. (2001) and for which...
GWcosmo is a package to estimate cosmological parameters using gravitational-wave observations with galaxy catalogues. Its current version for LVK Run O4 makes use of a precomputed ‘Line Of Sight Redshift Prior’, which encodes the redshift information of the galaxies and improves the computing time of the analysis.
