Related papers: Optimizing Active Seismic Isolation Systems in Gra…
We present a multi-scale optimal control framework for active seismic isolation in the Einstein Telescope, a third-generation gravitational-wave observatory. Our approach jointly optimizes feedback and blending filters in a cross-coupled…
In April 2020, KAGRA conducted its first science observation in combination with the GEO~600 detector (O3GK) for two weeks. According to the noise budget estimation, suspension control noise in the low frequency band and acoustic noise in…
General metric theories of gravity in four-dimensional spacetimes can contain at most six polarization modes (two spin-0, two spin-1 and two spin-2) of gravitational waves (GWs). It has been recently shown that, with using four GW…
We report on the optical, mechanical and structural characterization of the sputtered coating materials of Advanced LIGO, Advanced Virgo and KAGRA gravitational-waves detectors. We present the latest results of our research program aiming…
Gravitational waves from core-collapse supernovae are a promising yet challenging target for detection due to the stochastic and complex nature of these signals. Conventional detection methods for core-collapse supernovae rely on excess…
Heterodyne detection using microwave cavities is a promising method for detecting high-frequency gravitational waves or ultralight axion dark matter. In this work, we report on studies conducted on a spherical 2-cell cavity developed by the…
String cosmology models predict a relic background of gravitational wave produced during the dilaton-driven inflation. It's spectrum is most likely to be detected by ground gravitational wave laser interferometers (IFOs), like LIGO, Virgo,…
The existing high technology laser-beam detectors of gravitational waves may find very useful applications in an unexpected area - geophysics. To make possible the detection of weak gravitational waves in the region of high frequencies of…
In this paper, we develop a new approach to gravity-gradient noise subtraction for underground gravitational-wave detectors in homogeneous rock. The method is based on spatial harmonic expansions of seismic fields. It is shown that…
In this paper we discuss how the standard optimal Wiener filter theory can be applied, within a linear approximation, to the detection of an isotropic stochastic gravitational-wave background with two or more detectors. We apply then the…
The LIGO experiment aims to detect and study gravitational waves using ground based laser interferometry. A critical factor to the performance of the interferometers, and a major consideration in the design of possible future upgrades, is…
KAGRA is the first large-scale gravitational-wave detector with cryogenic test masses. Its target sensitivity is limited mostly by quantum noise in the observation frequency band owing to the remarkable reduction of thermal noise at…
Monitoring motion originating from ultra low-temperature cooling systems like cryocoolers is important for vibration sensitive cryogenic experiments like KAGRA. Since no commercial cryogenic accelerometers are available, we developed a…
The French-Italian interferometric gravitational wave detector VIRGO is currently being commissioned. Its principal instrument is a Michelson laser interferometer with 3 km long optical cavities in the arms and a power-recycling mirror. The…
Compact, high-precision inertial sensors are needed to isolate many modern physics experiments from disturbances caused by seismic motion. We present a novel inertial sensor whose mechanical oscillator fits on a standard one-inch diameter…
Parametric instability is an intrinsic risk in high power laser interferometer gravitational wave detectors, in which the optical cavity modes interact with the acoustic modes of the mirrors leading to exponential growth of the acoustic…
Tiny vibrations of mechanical structures are the main limiting cause in a number of high sensitivity measurement apparatus, chief among them the most sensitive displacement apparatus on earth: gravitational wave interferometers. Such…
The Virgo detector is a kilometer-length interferometer for gravitational wave detection located near Pisa (Italy). During its second science run (VSR2) in 2009, six months of data were accumulated with a sensitivity close to its design. In…
With the upgrade of current gravitational wave detectors, the first detection of gravitational wave signals is expected to occur in the next decade. Low-latency gravitational wave triggers will be necessary to make fast follow-up…
Optics is limited in the 'ray-approximation'-inclusion of wave properties result in additional phenomena and applications; interferometers and diffraction gratings are two manifestations of such non-geometric, physical optics. Incidentally,…