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, 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...
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.
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...
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 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...
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...
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...
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...
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...
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 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...
The communication of Italy's candidacy to host the Einstein Telescope is gaining momentum through multiple channels: institutional communication (website and social media), events at international, national, and regional levels — especially in the candidate area — and media engagement.
In this talk, we will present the latest updates on ongoing initiatives.
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...
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...
ETIC Lab Journey is an interactive web app designed to explore the laboratories of the ETIC (Einstein Telescope Infrastructure Consortium) project, an initiative by the Italian Ministry of University and Research, led by the National Institute for Nuclear Physics (INFN). Launched in 2023, the project has two main objectives: conducting a feasibility and site characterization study in Sos...
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,...
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...
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...
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...
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 (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...
Future gravitational wave observatories require significant advances in all aspects of their seismic isolation; inertial sensors being a pressing example. Inertial sensors using gram-scale, high Q factor, glass mechanical resonators combined with compact interferometric readout are promising alternatives to kilogram-scale conventional inertial sensors. We have developed a novel technique for...
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 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 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...
Magnetic noise will pose a significant limitation on the sensitivity of future Gravitational Wave (GW) detectors, such as the Einstein Telescope (ET), especially at low frequencies from a few Hz to approximately 100 Hz. This noise primarily originates from two sources: the natural terrestrial component (Schumann Resonances) and the environmental noise associated with the interferometer...
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...
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...
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...
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 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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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 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...
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...
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...
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 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...
We present the design and performance requirements of GEMINI, the first underground R&D facility dedicated to active seismic isolation and interplatform control for next-generation gravitational-wave observatories. The GEMINI site is located 1.4 km deep at the National Laboratories of Gran Sasso (LNGS). The facility consists of two actively isolated platforms operating in a vacuum, designed to...
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...
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...
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...
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...
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...
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...
