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.
In-situ monitoring and a good understanding of adsorption and desorption processes on cryogenic mirror surfaces are essential for the LF interferometers of ET and for ET-Pathfinder. A working group with members from UM, TNO and KIT work on a test setup focusing on two technologies for the monitoring of the growth of monolayers on cold surfaces, ellipsometry and microbalances. This poster...
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...
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...
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...
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 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...
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...
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 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...
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...
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...
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...
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 Research Center Jülich is part of a collaboration with the RWTH Aachen in developing dedicated items of the UHV system for the ET. One importing item is the protection of the detectors at the three key points of the triangular system. Therefore, a fast-closing shutter system should be developed. The investigations will comprise both numerical simulations, development of a technical system...
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...
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...
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...
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 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 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...
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...
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...
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,...
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...
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 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...
Beam expansion telescopes are required to match the coherent and squeeze fields generated in small crystals, to the ~km long optical cavities used in gravitational wave detection. To match any complex beam parameter to another, there are many possible solutions. These solutions have different robustness to focal length and positioning errors. In the context of the design of new gravitational...
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...
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...
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...
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 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...
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...
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...
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 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...
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...
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 (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...
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...
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...
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...
