E-TEST is a low-frequency suspension prototype developed for the Einstein Telescope, featuring a 100-kg test mass cooled to cryogenic temperatures (20–25 K) through radiative cooling techniques. The prototype is designed to provide compact seismic isolation at low frequencies (<10 Hz) while minimizing thermal noise, addressing the critical noise sources for next-generation gravitational-wave...
A variety of activities are currently being carried out at the Sos Enattos candidate site, encompassing systematic local noise monitoring, identification and characterization of potential noise sources, as well as engineering and geotechnical investigations. This presentation aims to provide an updated overview of the ongoing research efforts in Sardinia.
The LIGO-VIRGO-KAGRA observations are so far compatible with the Kerr black hole paradigm, though they cannot rule out entirely the existence of black hole mimickers. These are ultra-compact objects that reproduce some observable properties of black holes, while possibly predicting characteristic signatures such as non-trivial tidal deformability and/or repeated gravitational wave echoes in...
Black hole spectroscopy offers insights into the properties of black hole remnants. However, most models assume idealized, vacuum spacetimes, neglecting the astrophysical environments in which black holes reside.
Our most recent results show that the presence of matter halos, such as dark matter distributions, affects the quasinormal modes (QNMs) of black holes. We examined black holes...
The CAOS (Center for Applications on Gravitational Waves and Seismology) laboratory, part of the ETIC (Einstein Telescope Infrastructure Consortium) project, represents a significant Italian initiative designed for advancing third-generation gravitational wave detector technologies. CAOS has been envisioned as a hub for collaborative innovation and testing, particularly focusing on the...
The quasinormal mode spectrum plays a crucial role in modeling post-merger ringdown signals in binary coalescences, encompassing both black holes and ultracompact horizonless objects. However, quasinormal modes are highly sensitive to small deformations of the system and only describe the linear response within a limited and imprecisely defined timeframe after the merger. Motivated by a...
In August 2024, the Free State of Saxony officially declared its support for the ET site location bit for building the Einstein Telescope in the Lausitz (eng. Lusatia) region. The basement of this region is formed by the Lausitz Granodiorite Massif. The regional extent of the granodiorite is not known for certain, and recent observations contradict the historic geological maps in some...
Binaries of intermediate mass black holes (IMBHs) with masses $M_{\rm bh}=10^2-10^4 M_\odot$ are predicted to emit gravitational waves (GWs) potentially detectable with the Einstein Telescope. Though IMBHs of these masses are widely expected theoretically (and likely hosted in the centre of globular clusters and dwarf galaxies), these objects are very elusive and hard to detect with methods...
Fused silica fibres used in current ground-based gravitational wave detectors, such as Advanced LIGO, sustain loads of 40 kg with stresses reaching up to ~780 MPa in their thinnest regions. Reducing fibre diameter and increasing stress improves suspension thermal noise performance by improving damping dilution. In addition, the resonant modes are shifted to more favourable frequency ranges...
The work carried out in in the candidate site for the Einstein Telescope in the EMR to characterise the functioning of deep groundwater, and its quality will be presented. Particular attention will be paid to new piezometric measurement campaigns, the interpretation of hydraulic tests in boreholes and groundwater sampling campaigns. First data and interpretation will be presented. Future works...
To reach higher sensitivities in the frequency band below 10 Hz in third generation terrestrial gravitational wave detectors, such as the Einstein Telescope, the individual noise sources must be addressed and their impact on the system reduced. One of these noise sources is thermal noise, to be addressed through operating ET at cryogenic temperatures.
The cooling of the detector will...
The properties of the first stars in the Universe, known as Population III (Pop III) stars, and their remnants are still poorly understood. However, the increased sensitivity of next-generation gravitational wave observatories offers the potential to detect mergers of these early compact binaries at redshifts greater than 15. A fraction of these detections will be loud enough, that is, the...
The regional 3D model simulating groundwater flows in the candidate site for the Einstein Telescope in the EMR has been updated to better represent the interactions between the underground environment and the tunnels of the future telescope. The mesh around the tunnels has been refined and the injected zone around the tunnel modelled. The new results in terms of flows to be drained and impacts...
I will present the ESCAPE Virtual Research Environment (VRE), focusing on how an R&D gravitational wave pipeline, the Wavelet Detection Filter (WDF) can be run entirely in the ESCAPE Virtual Research Environment (VRE). The ESCAPE VRE is a modular, scalable platform to streamline scientific analysis, minimizing software environment setup and data discovery times. It is composed of an...
Population III (Pop. III) stars are ideal candidates for the formation of intermediate-mass black holes (IMBHs, $m = 10^2-10^5\,\rm M_{\odot}$) due to their small mass loss and top-heavy initial mass function. On the other hand, the masses of these IMBHs are typically limited to a few hundred solar masses, restricting their potential as massive black hole seeds. Star cluster dynamics can...
The test-masses for ET-LF present one of the most complex hardware design challenges in the whole project. We propose a conceptual design for the towers that is capable in principle of addressing several concerns: rigid mounting of the suspension system; interfaces with the cryogenic and cryogentic vacuum systems; and clean installation and access. The design simplifies the...
In the last years, gravitational wave detectors proved for the first time the existence of binary black hole mergers. Investigating their formation history can give us an useful insight on poorly constrained binary interaction processes. For instance, the properties of the binary black hole population are heavily influenced by the stability and efficiency of mass transfer events, since...
The stochastic gravitational-wave background (SGWB) generated by the inspiral and merger of binary neutron stars is traditionally modelled assuming that the inspiral is promptly followed by the collapse of the merger remnant to a rotating black hole. While this is reasonable for the most massive binaries, it is not what is expected in general, where a remnant is produced and may survive for up...
The rapid formation of supermassive black holes (SMBHs) in the early universe (z > 6) remains one of the most significant mysteries in the Universe. Observations of SMBHs with masses reaching ~ $10^{10} M_{\odot}$ within the first billion years challenge our understanding of black hole (BH) formation and growth. Despite significant insights from the James Webb Space Telescope (JWST), the...
Current gravitational wave (GW) detectors are observing hundreds of binaries in the low-redshift universe, but to fully understand formation mechanisms we must probe the high-redshift regime. Next-generation detectors, such as Cosmic Explorer and Einstein Telescope, will allow us access to redshifts greater than 20, and even upgrades to existing detectors may allow us to probe the...
Quantum chromodynamics predicts a phase transition from hadronic matter to deconfined quarks at extreme densities, yet its exact nature remains uncertain. Neutron stars offer a unique opportunity to probe this transition, but bulk properties—mass, radius and tidal deformability—provide only indirect signatures, which require many detections to resolve and are ineffective if the discontinuity...
Although it is conjectured that a phase transition from hadronic to deconfined quark matter is possible in the ultrahigh density environment in Neutron Stars, the nature of such a transition is still unknown. Depending on whether there is a sharp or slow phase transition, one may expect a third family of stable compact stars or “twin stars” to appear, with the same mass but different radii...
We present the results of three temporary deployments of seismic arrays, installed in two vertices of a possible configuration of ET in the area of the Italian candidate site (Sardinia). The experiments, aimed at investigating the local noise sources and the seismic velocity structure, were carried out in 2021 and 2024 with different geometrical layouts, number of sensors and total recording...
An understanding of differentially rotating relativistic stars is key to many areas of astrophysics, in particular to the emission of gravitational waves. A newly born, proto-neutron star or a compact
remnant of neutron stars binary merger are expected to rotate differentially and to be important sources of gravitational radiation. A highly accurate and stable, relativistic spectral code is...
Neutron stars having a mass smaller than about 1.17 Ms cannot be produced by any “standard” astrophysical mechanism. On the other hand, the analysis of SAX J1808.4-3658 has suggested a mass of about 0.8 Ms, or smaller (Di Salvo et al. MNRAS 483 (2019) 767) and a similar mass has been obtained by the analysis of HESS J1731-347 (Doroshenko et al. Nature Astronomy 2022). Also, masses and...
A designated area near the Sos Enattos mine (Lula, Nuoro Province, Sardinia, Italy) has been proposed as a candidate site for the Einstein Telescope (ET), a next-generation gravitational wave observatory requiring an exceptionally low-noise environment. To assess infrasound conditions relevant to ET, a set of infrasound microphones was installed at Sos Enattos, both on the surface and...
The Einstein Telescope (ET) is a proposed next-generation underground gravitational-wave detector in Europe, anticipated to enhance sensitivity by an order of magnitude compared to existing detectors while extending the observation band down to frequencies as low as 2 Hz. A thorough site characterization is critical for ET, considering geological, hydrogeological, and geotechnical conditions....
The Sardinian site, identified for the underground Einstein Telescope (ET) gravitational wave observatory, features a complex morphology with distinctive geological characteristics typical of stable crystalline basements. The area is also marked by deeply incised valleys, underscoring the need for a detailed and comprehensive understanding of the territory to support site assessment and risk...
Correlated seismic noise and the resulting Newtonian noise (NN), pose a significant challenge for future gravitational-wave detectors like the Einstein Telescope (ET), especially for low-frequency gravitational-wave background (GWB) searches.
The body-wave-induced NN could significantly impact ET's sensitivity to GWB by orders of magnitude in its most sensitive frequency band.
This study...
The Einstein Telescope (ET) will be Europe's next-generation underground interferometric gravitational wave detector. The extreme target sensitivity that these detectors should attain requires underground placement to shield the apparatuses from the ambient noise. A quiet environment in a geologically stable area away from major faults and industrial activities also helps to maximise the duty...
A new large-scale research center is established in Lusatia, the German Centre for Astrophysics (DZA). One part of this will be the Low Seismic Lab (LSL), which is to be built in the Lusatian granodiorite in the region between the eastern German cities Hoyerswerda, Kamenz and Bautzen. This underground laboratory is a place of seismic tranquility, which is required for the trouble-free...
The Einstein Telescope aims to improve sensitivity by at least an order of magnitude compared to current detectors. The dominant noise source in the region of 1 to 10 Hz is expected to be Newtonian Noise (NN) from seismic activity in the surrounding rock. In order to reach the desired sensitivity, NN must be actively mitigated. Seismometers will be installed in boreholes around the mirrors to...
Characterizing the seismic impact of nearby wind turbines is crucial for future gravitational wave detectors like the Einstein Telescope.
Their vibrations pose a challenge to gravitational wave detection especially in the low frequency range where direct and gravitational couplings are the limiting factors.
This poster will explore and discuss the influence of different wind turbine tower...
Increasing the sensitivity of gravitational wave detectors is a highly complex challenge which requires their stable operation at progressively higher power levels. Optical power absorption in the Fabry-Perot cavities leads to thermally induced aberrations that, if not compensated, degrade the interferometer's performance. Therefore, the measurement and correction of these optical aberrations...
Future high-power operation of Einstein Telescope (ET) in its high-frequency dedicated incarnation (ET-HF), is expected to amplify the impact of thermally-induced optical aberrations, posing new challenges for beam quality and interferometric stability. Building on the legacy of thermal compensation systems developed for Advanced Virgo, we are currently investigating advanced wavefront sensing...
The detection of information carried by means other than electromagnetic waves has opened a new era in the study of the Universe. Very Long Baseline Interferometry, thanks to its exquisite angular resolution, remains the only technique allowing astronomers to directly image the most compact structures associated with the emission of energetic photons or other carriers of information, as well...
The third generation Gravitational Wave detectors such as the Einstein Telescope, and the future instruments for astronomy and astrophysics to be released in the next years will generate an increased amount of data of considerable complexity, that will be available to the astrophysics community. This poses important challenges in order to store, process, integrate, distribute, share and...
We present updates on the modelling work happening in Glasgow towards the design of prototypes for the next generation of suspensions. The previous models of advanced LIGO are reviewed, and the effect of deviations from ideal scenarii on the suspension thermal noise are studied. As we make progress towards the definition of parameters for our cryogenic suspension, bond strength trials and...
This presentation provides an update on the feasibility analysis of a novel suspension for the cryogenic test-mass mirrors of the low-frequency detector of the Einstein Telescope. To overcome the severe limitation imposed on traditional suspensions by the tensile stress for simultaneously achieving low thermal noise, safer mechanical margins and high thermal conductance, this configuration...
The next-generation gravitational wave observatory, Einstein Telescope, requires coatings with extremely low losses to enhance its sensitivity. Our research focuses on the development and characterization of oxide and nitride coatings deposited using sputtering techniques. We investigate how impurities and stoichiometry influence their properties.
To this end, we have established new...
As gravitational wave detectors continue to advance, enhancing their sensitivity remains a crucial challenge. Performance is limited by various noise sources, including seismic, thermal, and quantum noise. Developing techniques to mitigate these limitations is essential for the development of the Einstein Telescope interferometers.
The AEI 10m Prototype is a prototyping facility closely...
The Einstein Telescope (ET) and Cosmic Explorer (CE), as next-generation gravitational-wave (GW) observatories, will achieve unprecedented sensitivity, detecting an immense number of GW signals across an extended frequency range. This improvement introduces a fundamental challenge: the presence of overlapping GW events in both time and frequency, complicating signal extraction and parameter...
CALVA is an experimental facility at IJCLab (Orsay, France), hosting a 50-m long suspended optical cavity. It is mainly dedicated to quantum noise reduction experiments with the development of an in-vacuum squeezing source and a linear three-mirror cavity as squeezing filter cavity. In this poster I will present the infrastructure, the on-going experiments and the projects foreseen for...
We investigate the detectability of continuous gravitational waves (CW) - weak, long-duration signals emitted by asymmetric, rotating neutron stars (NS). Despite current gravitational wave detectors not yet providing a confident detection, future instruments, notably the Einstein Telescope (ET), could move CW signals from theory to observation. Our analysis estimates the number of isolated...
We explore the potential of cross-correlation between gravitational waves (GWs) and 21 cm intensity mapping (IM) from neutral hydrogen emission (HI), focusing on its role in view of future high-precision observatories, specifically Einstein Telescope (ET) and the Square Kilometer Array Observatory (SKAO). We model the large scale structure evolution by making use of 3D lightcones of the dark...
LIGO and Virgo are limited in the amount of power they can build up in the arms. The limitation arises from the absorption of optical power in the main optics, causing mirror surface deformations. This in turns couples scatters light into higher order modes and causes several problems, notably, parametric instabilities, degraded buildup of the control sidebands and limited squeezing...
One of the key requirements for achieving the expected sensitivity in detecting weak gravitational waves is to secure an area free from both natural and anthropogenic noise. For this reason, the proposed Italian site for the Einstein Telescope is located adjacent to the former Sos Enattos metalliferous mine in northeastern Sardinia (Province of Nuoro). Sardinia’s unique tectonic setting—as a...
At low frequencies (1-100 Hz), the dominant noise sources for the Einstein Telescope (ET) will be of seismic and magnetic origin. In particular, magnetic noise can be categorized into natural noise, primarily caused by Schumann resonances, and self-inflicted noise, generated by the interferometer’s own electronics.
Based on experience from Virgo, achieving the target sensitivity will...
Many pieces of evidence point to existence,
at least at en effective level,
of a lower limiting length of quantum origin.
A mathematical tool is here presented which accomplishes the task
of endowing spacetime with a description of distances
with a minimum length incorporated, meaning that distances between
any two space or time separated points tend to a finite limit
when the points go...
The Code of Conduct defines the expected behaviour within the ET Collaboration and serves as the foundation for maintaining a professional, ethical, and respectful research environment.
As an international collaboration that brings together diverse cultural backgrounds and work styles, ET values inclusivity and cooperation. Scientific achievements are meaningful not only for their impact but...
This study aims to characterize the seismic noise at the CAOS construction site to support the development and testing of suspension systems for gravitational wave interferometers, such as the Einstein Telescope.
This contribution addresses a first feasibility study for the measurement of millihertz Gravitational waves (mHz GWs) with a storage ring-based detector design that might aid in noise mitigation for Einstein Telescope (ET) by providing a terrestrial gravity noise (TGN) signal and could potentially enable multiband GW observations from Earth.
We propose an experiment based on the measurement...
The work explores the application of Deep Reinforcement Learning (DRL) to optimize the locking procedure of high-finesse Fabry-Perot (FP) cavities, critical components in Gravitational Wave (GW) detectors. Improving and speeding up the locking procedure for a correct resonance acquisition of these cavities aim to improve the detector’s duty cycle, enhancing the Science Mode time (Accadia et...
Newtonian noise (NN), arising from local density fluctuations due to seismic activities will limit the sensitivity of next-generation gravitational wave detectors at low frequencies. This study explores deep learning models as non-linear algorithms to predict and cancel NN.
As a preliminary experiment prior to obtaining Einstein Telescope data, we utilise data from the Virgo detector,...
In this talk we will present a physics-informed autoencoder designed to encode the equation of state of neutron stars into an interpretable latent space. The input polytropic EoS is encoded in the mass, radius, and tidal deformability values of a neutron star. Unlike traditional black-box autoencoders, our approach incorporates additional loss functions to enforce explainability in the encoded...
Understanding the ambient seismic noise field and its attenuation with depth is an important consideration for the decision to build the Einstein Telescope at a proposed site. Here, we perform 2D and 3D ambient noise simulations for the Lausitz region by solving the seismic wave equation using Spectral Element Method (SEM), a high-fidelity numerical technique capable of handling complex...
The aim of this work is obtaining a preliminary estimate of expected crustal deformation in Sardinia due to geodynamical processes acting on local and regional scales in response to the past and present variations of surface loads. Solving the “Sea Level Equation” for a spherically symmetric, self-gravitating visco-elastic Earth, we characterize the ongoing vertical and horizontal movements in...
The low-frequency frontier is amidst the most important challenges for future gravitational waves detectors. Improved low-frequency sensitivity is crucial for detecting high-mass or high-z systems, improving source localisation, enabling timely alerts for electromagnetic follow-ups, and facilitating the detection of predicted gravitational waves from sources like rotating pulsars. In this...
At the Einstein Telescope, Newtonian noise is expected to be the dominant noise for low frequencies. Its impact is proposed to be reduced with the help of an array of seismometers that will be placed around the interferometer endpoints. As boreholes for seismometers are expensive, their positions should be optimized. Up to now this was done based on an analytical calculation that makes...
In gravitational interferometry increasing the measuring laser power is a straightforward way to improve the instrument sensitivity, and it has been one of the main points in the upgrades of the existing detector like VIRGO and in the design of future projects like ET. However, the dissipated portion of the high circulating power in Fabry-Pérot arm cavities is enough to heat up and deform the...
The CAOS research center (Centro per Applicazioni sulle Onde gravitazionali e la Sismologia) is under construction in Perugia to test seismic attenuation systems for ET and Virgo and perform seismological research. Two 13 m tall attenuators are currently being designed and manufactured, based on the Advanced Virgo Superattenuator concept to support a suspended Fabry-Pérot cavity with 100 kg...
In the context of gravitational wave detectors, optical aberrations primarily arise from laser absorption in coatings and production process defects in the various optics along the laser path. If uncorrected, these distortions can significantly deviate the detector from its optimal working point, making the interferometer unmanageable and drastically reducing its sensitivity. Therefore, the...
The Superattenuator is a cornerstone in seismic isolation systems for ground-based interferometers and is indicated as the reference solution for the isolation of the test masses of the Low-Frequency Einstein Telescope.
However, the need for an update of the Superattenuator arises not as much from the increased sensitivity requirements, as from the need to suspend a heavier, cryogenic...
The Laboratory of Architecture and Territory, whose members are all architects and researchers from the Department of Civil, Environmental Engineering and Architecture (DICAAR) of the University of Cagliari, Italy, explore the potential of designing research infrastructures and their spatial components by considering territorial systems. in recovering the material and immaterial value of a...
The Italian Einstein Telescope Infrastructure Consortium (ETIC) is an initiative led by INFN aimed at establishing a network of laboratories crucial for the future Einstein Telescope gravitational wave interferometer, alongside characterization efforts for the Sos-Enattos site in Sardinia, Italy. This poster will present the GALILEO project for the Einstein Telescope, planned to be set up at...
The Einstein Telescope will consist of 120 km of vacuum pipes with a diameter of 1 m to achieve the required design sensitivity. The BeamPipes4ET project introduces an innovative production concept for these vacuum pipes by manufacturing them on-site in the tunnels through a continuous process using coils of sheet metal. This minimizes the transportation needs - forming the key concept of...
The ERC project GRAVITHELIUM aims to investigate the dissipative behaviour of full-scale suspensions used to cool-down the cryogenic core optics in ET-LF. Two possible suspension concepts are currently considered, using either monocrystalline suspension fibres made of silicon or sapphire, or titanium suspension tubes filled with static He-II. The dissipative behaviour of these suspensions is...
We present a new method for incorporating gravitational wave (GW) sources into cosmological simulations of galaxy formation. Our approach, implemented in the moving-mesh code Arepo, associates the properties of merging binary systems – black hole-black hole, black hole-neutron star, and neutron star-neutron star – with star particles representing a single stellar population (SSP) in...
Gravitational waves (GWs) detectors have been upgraded over time to enhance their sensitivity, pushing the limits imposed by their infrastructure.
Next generation observatories, Einstein Telescope and Cosmic Explorer, are currently under design, aiming for significant improvement in sensitivity that can have significant implications in scientific research. Among them, the possibility of...
Thermal gradients in the Input Test Masses (ITM) introduce optical aberrations that pose a critical challenge for both current and next-generation gravitational wave (GW) interferometers, significantly affecting their stability and sensitivity. Using the temperature map obtained through finite element analyses, the optical path difference (OPD) caused by thermal lensing and the deformation of...
In ET-HF it is expected that there will be optical aberrations due to thermal deformation of test masses. The aberrations will influence the sensitivity but less is known about the expected aberration order of magnitude or shape. In our study, we tackle the optical measurement of the aberration by simulating the optical read-out via a Hartmann wavefront sensor. We study the sensor components...
The Einstein Telescope, as a third-generation gravitational wave detector, aims to improve the sensitivity of the detection band in the low-frequency region over existing gravitational wave detectors. For this, displacement sensors that provide high sensitivity between 100 mHz and 200 Hz are required for seismic isolation, and the scientific community is striving to increase their sensitivity...
The pursuit of next-generation gravitational-wave detectors, such as the Einstein Telescope, with its ambitious goals for sensitivity, places extreme demands on the complex systems controlling the position of suspended mirrors. Operating in underground environments with exceptionally low seismic noise and targeting an extended bandwidth from low to high frequencies, these systems require...
The current measurement scheme for a broadband quantum noise reduction in GW detectors relies on 300 m long and detuned filter cavities, that has been stunningly proven in Advanced LIGO and successfully commissioned in Advanced Virgo, for the run O4.
Nevertheless, they add infrastructural complexity and optical losses on top of an already large instrumental apparatus. Moreover, ET will need...
In the context of Gamma-Ray Bursts (GRBs) astrophysics, the class of short GRBs is particularly fascinating since they are expected to be produced in compact binary mergers, and to be associated with gravitational wave (GW) events. Double neutron star or neutron star-black hole binaries likely generate another electromagnetic transient, known as Kilonova (KN). As such, with the present and...
We analyze GW190425 and GW170817 within a scenario in which strange quark stars (QSs) coexist with neutron stars. We will conclude that:
- GW190425 could be a QS-QS merger, producing a supramassive QS;
- a QS-QS merger produces a weak KN signal (which could have passed undetected in the case of GW190425);
- the material ejected in the post-merger is mostly flowing in the equatorial plane,...
Gravitational-wave (GW) observations of compact binaries have the potential to unlock several remarkable applications in astrophysics, cosmology, and nuclear physics through accurate measurements of the source luminosity distance and inclination. However, these parameters are strongly correlated when performing parameter estimation, which may hamper the enormous potential of GW astronomy. We...
Prediction and mitigation of noise can increase the sensitivity of future gravitational wave detectors like the Einstein Telescope. These mitigation techniques could reduce noise from sources that can be independently measured, like seismic, electromagnetic, or acoustic disturbances. Wiener filters are a common technique that has been tested in current detectors. We are exploring the potential...
The CAOS (Centro per Applicazioni sulle Onde gravitazionali e la Sismologia) facility is currently under construction in Perugia, Italy. It will host a short Fabry-Perot cavity to carry out dedicated R&D on seismic attenuation systems for ET, specifically enabling the development of two AdV-like Superattenuators (SAs), a technology that represents the ET reference solution as envisaged in its...
In the current Virgo setup, quantum noise reduction is achieved by injecting squeezed vacuum states in the interferometer dark port. For their generation and phase stabilization with respect to the interferometer carrier, low-noise phase locked loops (PLL) and direct digital synthesizers (DDS) are used. An RF-mixer based architecture is under investigation for the development of an...
The advent of the Einstein Telescope (ET) will revolutionize our understanding of binary neutron star (BNS) mergers, with a huge number of gravitational wave (GW) detections expected every year, spanning about 10 billion years of cosmic history. As demonstrated by the GW170817 event, the greatest scientific potential is held by multi-messenger observations combining the GW signal with the...
The first direct detection of gravitational waves (GWs), back in 2015, marked the beginning of a new era for the study of compact objects, and the upcoming next-generation detectors, such as Einstein Telescope (ET), are expected to add hundreds of thousands of compact binary coalescences to the list. We discovered up to 90 GW signals, from which we were able to put some constrains on the...
The present generation of interferometers has demonstrated that gravitational-wave observations, even in the absence of electromagnetic counterparts, i.e. dark sirens, can serve as an independent method to investigate the Hubble tension. However, while the proposed designs for the Einstein Telescope (ET) can produce astonishingly precise $H_0$ measurements, it has been shown that incorrect...
Precise displacement sensing with femtometer or sub-femtometer readout noise at frequencies below $10\,\mathrm{Hz}$ is extremely beneficial for the ET active isolation systems. Here, we present a laser interferometric sensor, named heterodyne cavity-tracking, designed for high-precision relative displacement readout. The scheme utilizes a heterodyne-stabilized optical cavity, incorporating the...
MezzoCielo, meaning "half of the sky," represents one of the most advanced developments in the class of all-sky survey telescopes. This revolutionary design is built around a fully spherical refractive optical element, filled with a highly transparent, low-refractive-index liquid, and surrounded by a large array of identical cameras. By leveraging this unique optical architecture, MezzoCielo...
UpGLADE is an upcoming extensive galaxy catalogue which will include more than a billion objects from various non-independent surveys, providing redshift information, which is fundamental for gravitational-wave (GW) cosmology – particularly for Hubble constant inference using dark sirens and galaxy catalogue. Moreover, UpGLADE will play a crucial role in multi-messenger astronomy by supporting...
Electrostatic charging on the surfaces of the optical elements is a limiting noise source for gravitational wave detectors (GWD) already at room temperature. The charge accumulation has been already observed in LIGO and possibly in Virgo.
The electrostatic charging mechanism of the mirrors may be mainly caused by local electrostatic (LIGO) or electro-magnetic (Virgo) controls.
Another...
The gravitational waves from the binary neutron star merger GW170817 were accompanied by a multiwavelength electromagnetic counterpart, which confirms the association of the merger with a short gamma-ray burst (sGRB). The afterglow observations implied that the event was accompanied by a narrow, ~5°, and powerful, ~1e50 erg, jet. We study the propagation of a Poynting flux-dominated jet within...
We present the results of a gravimetric study conducted in the Sos Enattos mining site (northeastern Sardinia), an area identified as the Italian site for the potential underground installation of the Einstein Telescope (ET), a third-generation gravitational wave detector.
Currently, the ET project is in its preparatory phase, with efforts focused on performing feasibility studies for...
Euclid is an ESA space mission launched in July 2023, designed to produce an all-sky map of galaxies with unprecedented precision. The mission will survey 14,500 square degrees with its Wide Survey, providing photometric redshifts for galaxies in the range $0
The increasing power levels injected into interferometric gravitational wave detectors have highlighted the impact of localized defects on the high-reflectivity (HR) surfaces of the main optics. These defects, originating from coating inhomogeneities, substrate imperfections, or localized absorbers, can degrade detector performance by introducing aberrations in the optical wavefront, leading...
The huge luminosity, the redshift distribution extending at least up to z~10 and the association with the explosive death of very massive stars make long GRBs extremely powerful probes for investigating the early Universe (pop-III stars, cosmic re-ionization, SFR and metallicity evolution up to the “cosmic dawn”) and measuring cosmological parameters. At the same time, as demonstrated by the...
At the Department of Physics and Earth Sciences at the University of Ferrara we have a sensitive polarimeter for birefringence measurements of both substrates and coatings. In the configuration for substrate measurements the polarimeter is based on two co-rotating half-wave plates with the sample between them. The induced time dependent ellipticity signal is then extracted using a heterodyne...
We present an evaluation of how site dependent noise can affect the signal to noise ratio (SNR) of compact binary coalescence (CBC) signals in the future 3rd generation gravitational wave (GW) detector Einstein Telescope (ET). The design of ET is currently pushing the scientific community to study its scientific potential with respect to known, and possibly unexpected, GW signals using its...
We present an updated estimation of the noise induced by scattered light inside the main arms of the Einstein Telescope (ET) gravitational wave detector. Both ET configurations for high- and low-frequency interferometers are considered. The new studies include the cryotrap areas close to the main mirrors, consider both 10km and 15km arms, and explore possible mis-alignments of the laser beam...
As straylight is an important limitation for the sensitivity of gravitational wave detectors, we investigate new laser operation concepts and interferometer topologies for a more straylight-resilient detector configuration.
Our main focus is the use of tunable coherence realized by phase modulation following a pseudo-random-noise (PRN)-sequence on the interferometer laser. This breaks the...
Next-generation gravitational wave (GW) observatories such as the Einstein Telescope (ET) will observe large numbers of binary neutron star (BNS) mergers across cosmic history and allow us to obtain precise parameter estimates for the events observed at low redshifts. The Vera Rubin Observatory will be a powerful instrument in the discovery and follow-up of optical counterparts of BNS mergers...
I will review the connection between binary neutron star mergers, cosmic rays, and ultra high energy neutrinos. I will discuss the possibility of a multimessenger joint detection of gravitational waves and neutrinos from such mergers.
Limburg, a region located in the cross-border area between The Netherlands, Belgium, and Germany is the Euregio-Meuse-Rhine candidate site for hosting the Einstein Telescope. Recent studies to investigate the site’s subsurface suitability for hosting Einstein Telescope has seen several boreholes being drilled and deployment of arrays of geophones on the surface. In this study we present a 3D...
The Einstein Telescope (ET) will extend the reach of gravitational wave (GW) astronomy for stellar-mass compact binaries to unprecedented distances, significantly enhancing opportunities for multi-messenger discovery. Building on the landmark observations of GW170817 and informed by our recent population modeling studies (Colombo et al. 2022, 2024), we investigate the prospects for detecting...
Quantum Noise (QN) limits the sensitivity of ground-based Gravitational Wave (GW) interferometers (ITF) across all the frequency bandwidth (10Hz - 10kHz) [1]. Current detectors are designed to achieve broadband QN Reduction (QNR) via frequency-dependent squeezing (FDS) generated in reflection of a 300 m long detuned filter cavity (FC) that is coupled with a frequency-independent squeezing...
The Lausitz is the third potential site to host the Einstein Telescope (ET). Site characterization is in progress since late 2023 based on the ongoing survey for a planned underground laboratory „Low Seismic Lab“ (LSL). The LSL will be a central part of the Deutsche Zentrum für Astrophysik (DZA, German Center for Astrophysics) which is currently being established. Site requirements for the LSL...
Increasing the optical circulating power in gravitational-wave detectors is a straightforward way of increasing detection sensitivity. However, current detectors are limited in the amount of achievable circulating power far below the design values. Optical absorption in the test masses and main optics leads to thermal effects that shift the eigenmodes of the optical cavities and cause control...
We present SEOBNRv5THM, an accurate and fast gravitational-waveform model for quasi-circular, spinning, non-precessing binary neutron stars (BNS) within the effective-one-body (EOB) formalism. It builds on the binary-black-hole approximant SEOBNRv5HM and, compared to its predecessor SEOBNRv4T, it i) incorporates recent high-order post-Newtonian results in the inspiral, including higher-order...
The CAOS facility in Perugia serves as a specialized lab for testing mechanical and optical systems for the Einstein Telescope (ET). It will host a seismic-isolated Fabry-Perot cavity. The current research and development efforts include testing ET's full-sized Super Attenuators, creating integration tools and procedures for lateral-entry payload access at the base of the tower, and evaluating...
There are a few examples where the accuracy of theoretical predictions is running ahead of that of experiments. One is the case of gravitational waves naturally sourced by hydrodynamical fluctuations in a thermal medium. These signals are motivated by the Standard Model of particle physics, predicting that, for the first three hundred thousand years, the fundamental constituents of the matter...
Wide-band searches for continuous gravitational waves are essential to reveal unknown neutron stars that may be close enough to us to be detectable. Currently, analyses performed on data from 2G detectors for unknown sources cover all possible sky directions, but are restricted in the rotational parameters by their computational cost and by the limited bandwidth of the detectors at low...
A significant challenging feature of the ET vacuum system is the requirement on the hydrocarbon partial pressure ($p_{hy}$) for molecules heavier than 100 atomic mass unit (amu), as explained in the ET design report
\begin{equation}
p_{hy}\le1\cdot10^{-14}\,mbar
\end{equation}
In order to reach such an ambitious result, both the non volatile and volatile residue of hydrocarbons should...
The Vera Rubin Observatory’s (VRO) Legacy Survey of Space and Time (LSST) will revolutionize time-domain optical astronomy, detecting faint sources down to r~27.5 mag and generating nearly 32 trillion observations over 10 years. Among these, ~10 million will be supernovae (SNe), covering a wide range of redshifts and enabling studies of known and rare types, progenitors, and strongly lensed...
I will discuss a recent first-principle derivation of the spectral features of astrophysical stochastic backgrounds produced by populations of compact binary coalescences (CBCs). The treatment is based on the observation that, among the parameters characterizing a CBC, some of them (extrinsic) are distributed uniformly following symmetry principles, while other (intrinsic) carry the more...
Binary black hole systems are typically assumed to evolve in vacuum. However, the environment surrounding the binary components can influence their properties, such as their tidal deformability, affecting the gravitational waveform produced by the binary and its interpretation in gravitational wave data analysis.
In this talk, focusing on next-generation experiments, such as the Einstein...
We present an evaluation of how site dependent noise can affect the signal to noise ratio (SNR) of compact binary coalescence (CBC) signals in the future 3rd generation gravitational wave (GW) detector Einstein Telescope (ET). The design of ET is currently pushing the scientific community to study its scientific potential with respect to known, and possibly unexpected, GW signals using its...
In the Summer of 2024, the Discovery Museum in Kerkrade and Maastricht University started the Einstein Telescope Education Centre (ETEC), a four-storey exhibition and learning facility for gravitational waves and its instrumentation, intended for upper classes of secondary education in the EMR-region. In one year of operation, ETEC has hosted many school classes, giving them a day-programme on...
This talk will present the analysis of the first ET MDC using the pygwb pipeline to search for an isotropic stochastic background. We compare the measurement to the theoretical prediction derived from the list of sources and quantify the differences, providing valuable insights into stochastic searches in the presence of high signal-to-noise ratio signals. Additionally, we will discuss the...
The title of this paper, a clear paraphrase of Eugene Wigner’s renowned essay on the role of mathematics in the natural sciences, is intended to highlight the epistemological significance of analogical reasoning—a process that the history of science has shown to be pivotal across numerous domains and in a wide range of discoveries. The resemblance between concepts, the referencing and...
Primary and lower secondary school students are naturally curious, often exhibiting a "little scientist" attitude. However, curiosity alone is not enough for developing structured scientific thinking, essential for their education. We present the GRAVIS project, an educational program which brings together gravitational waves physics and digital storytelling to engage students in inquiry-based...
Gravitational wave science, and instrumentation in particular, has a surprisingly strong connection to the typical secondary curriculum in secondary education. As such, Einstein Telescope offers great opportunities for teachers and students, and is ideally suited to show students that they too can understand the newest discoveries, practice the physics of their high school curricula in an...
The Einstein Telescope (ET) Preparatory Phase project is a Horizon Europe-funded infrastructure project that aims to support critical activities of the ET community in the preparatory phase of the experiment, including technical design, costing and site selection for the observatory and identification of ET’s scientific, socio-economic and environmental impact. Work Package (WP) 10 of ET-PP...
Unmodeled data analysis techniques in the LVK collaboration, particularly coherent Wave Burst (cWB), do not assume any physical constraints when detecting GW events. While this allows for the detection of unmodeled signals with great efficiency, it limits the ability to accurately estimate source properties in the case of CBCs. Physics-Informed Neural Networks (PINNs) offer a promising...
In this session, we’ll dive into the Einstein Telescope’s supranational social media activities. Over the past months, we’ve accelerated our efforts - launching new profiles, broadening our reach, and sharing a diverse range of content. Together, we’ll examine real examples and brainstorm ways to elevate our strategy. We’ll use the “Rose–Bud–Thorn” exercise to highlight successes, identify...
The Einstein Telescope (ET) and other third-generation (3G) gravitational wave (GW) detectors will be key instruments for detecting gravitational waves (GWs) in the coming decades. However, analyzing the data and estimating source parameters will be challenging, especially given the large number of expected detections—between $10^4$ and $10^5$ per year—which makes current methods based on...
Third-generation ground-based gravitational wave detectors such as the Einstein Telescope are expected to significantly advance our understanding of compact binary coalescences. One of the most critical challenges in data analysis for the Einstein Telescope is that of overlapping signals. With a tenfold improvement in sensitivity, the Einstein Telescope will be able to detect binary black hole...
Third-generation (3G) gravitational wave (GW) observatories will unveil a cosmic orchestra, detecting thousands of sources annually. However, their increased detection rate poses a major challenge for data analysis. Existing, widely used techniques to obtain the source parameters are prohibitively expensive, creating a bottleneck for extracting scientific insights from 3G detector data. We...
We will develop first ideas for interesting & informative visual outreach materials, exploring the science, technology, international team & social impact of the Einstein Telescope. We are looking for input from ET members across the project, working in different areas and roles.
In recent months, the Einstein Telescope Preparatory Phase (ET-PP) communication group has undertaken several key initiatives to strengthen the project’s visibility, cohesion, and engagement with diverse audiences. We will present the newly developed ET webpage, designed to serve as a central, accessible platform for sharing updates, project milestones, and outreach materials. We will also...
For the detection of gravitational waves with the Einstein Telescope very high requirements regarding sensitivity must be met. The telescope is designed to be able to detect changes in length twenty-six orders of magnitude below its own size. Due to the required sensitivity the number of disturbance factors, such as seismic noise, that must be overcome, is extensive. This leads to the...
