A5051278780- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Cold Atom Physics and Bose-Einstein Condensates
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Advanced Frequency and Time Standards
- High-pressure geophysics and materials
- Seismic Waves and Analysis
- Superconducting Materials and Applications
- Statistical and numerical algorithms
- Atomic and Subatomic Physics Research
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Advanced MEMS and NEMS Technologies
- Mechanical and Optical Resonators
- Astronomical Observations and Instrumentation
- Inertial Sensor and Navigation
- Advanced Fiber Laser Technologies
- Black Holes and Theoretical Physics
- Magnetic confinement fusion research
- Scientific Measurement and Uncertainty Evaluation
- Superconducting and THz Device Technology
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2014-2024
Istituto Nazionale di Fisica Nucleare
2018
European Gravitational Observatory
2008
University of Ferrara
2005
University of Padua
1998-2004
We propose an under-ground experiment to detect the general relativistic effects due curvature of space-time around Earth (de Sitter effect) and rotation planet (dragging inertial frames or Lense-Thirring effect). It is based on comparison between IERS value vector corresponding measurements obtained by a tri-axial laser detector rotation. The proposed consists six large ring-lasers arranged along three orthogonal axes. In about two years data taking, 1% sensitivity required for measurement...
A search for a new scalar field, called moduli, has been performed using the cryogenic resonant-mass AURIGA detector. Predicted by string theory, moduli may provide significant contribution to dark matter (DM) component of our Universe. If this is case, interaction ordinary with local DM forming Galaxy halo, will cause an oscillation solid bodies frequency corresponding mass moduli. In sensitive band AURIGA, some 100 Hz at around 1 kHz, expected signal, Q=△f/f∼10^{6}, narrow peak, △f∼1 mHz....
This paper presents the results of observations detectors participating in International Gravitational Event Collaboration (IGEC) from 1997 to 2000 and reviews data analysis methods. The is designed search for coincident excitations multiple detectors. set analyzed this article covers a longer period more complete than that given previous reports. current accurate determining false dismissal probability time coincidence it optimizes with respect target amplitude direction signal. statistics...
We report the initial results from a search for bursts of gravitational radiation by network five cryogenic resonant detectors during 1997 and 1998. This is first significant with more than two observing simultaneously. No wave burst was detected. The false alarm rate lower 1 per 10(4) yr when three or were operating typical threshold H approximately 4x10(-21) Hz-1 on Fourier component at 10(3) Hz strain amplitude. New upper limits amplitude have been set.
We present the concept of a sensitive and broadband resonant mass gravitational wave detector. A massive sphere is suspended inside second hollow one. Short, high-finesse Fabry-Perot optical cavities read out differential displacements two spheres as their quadrupole modes are excited. At cryogenic temperatures, one approaches standard quantum limit for operation with reasonable choices cavity finesses intracavity light power. molybdenum detector, overall size 2 m, would reach spectral...
We have recently shown that the very low mechanical energy achieved and measured in main vibration mode of gravitational wave bar detectors can set an upper limit to possible modifications Heisenberg uncertainty principle are expected as effect gravity. Here we give more details on data analysis procedure allows one deduce (i.e., meaningful parameter for our purpose). Furthermore, extend results, discussing their implication physical models face quantum gravity from different points view,...
A new signal extraction chain for gravitational wave bar detectors is proposed. Signal transduction made by means of a Fabry–Perot cavity. Using reference cavity frequency comparison sensitivity hmin=3×10−20 with bandwidth about 50 Hz estimated an ultracryogenic detector. The first prototype implementation as well room-temperature measurements on it are reported.
The International Gravitational Event Collaboration, IGEC, is a coordinated effort by research groups operating gravitational wave detectors working towards the detection of millisecond bursts waves. Here we report on current IGEC resonant bar observatory, its data analysis procedures, main properties first exchanged set. Even though available set not complete, in years 1997 and 1998 up to four were simultaneously. Preliminary results are mentioned.
A setup for measuring mechanical losses of silicon wafers has been fully characterized from room temperature to 4K in the frequency range between 300Hz and 4kHz: it consists with nodal suspension capacitive optical vibration sensors. Major contributions are investigated compared experimental data scanning full range; particular, due thermoelastic effect wafer clamp modeled via finite element method analysis; surface gas damping also estimated. The reproducibility measurements total is...
We have implemented likelihood testing of the performance an optimal filter within online analysis AURIGA, a sub-Kelvin resonant-bar gravitational wave detector. demonstrate effectiveness this technique in discriminating between impulsive mechanical excitations and other spurious excitations. This also ensures accuracy estimated parameters such as signal-to-noise ratio. The efficiency to deal with nonstationary noise its application data from network detectors are discussed.
Ring lasers are inertial sensors for angular velocity based on the Sagnac effect. In recent years they have reached a very high sensitivity and accuracy; best performing one, ring Laser G in Wettzell (Germany), square with 16 m perimeter, has of 12prad/s close to shot noise limit inferred from ring-down time measurements. On this basis it is expected that an array six 36 can perform 1% accuracy test measurement Lense-Thirring frame dragging after 2 integration time. Essential comparison...
We report on the design of new suspension system for gravitational wave bar detector AURIGA. The was designed with aid finite element modeling simulations goal achieving at least −240dB vibration reduction 900Hz in a cryogenic environment, while preserving high mechanical quality factor. room temperature measurements core stage, mode frequencies, and attenuation we discuss them basis simulation predictions. is currently installed detector, which properly working operating 4.2K. observed...
The groups operating cryogenic bar detectors of gravitational waves are performing a coordinated search for short signals within the International Gravitational Event Collaboration (IGEC). We review most relevant aspects data analysis, based on time-coincidence among triggers from different detectors, and properties exchanged by each detector under recently-upgraded agreement. IGEC is currently analysing observations 1997 to 2000, when up four were simultaneously. 10% 50% this time period...
We present the status of ultracryogenic gravitational wave detector AURIGA, which is taking data since may 1997 with an energy sensitivity in mK range and bandwidth greater than 1 Hz. The typical output summarized daily reports are important tools for diagnostic checking vetoes periods unsatisfactory operation detector.
In the last few decades, much effort has been made for production of squeezed vacuum states in order to reduce quantum noise audio-frequency band. This technique implemented all running gravitational-wave interferometric detectors and helped improve their sensitivity. While are acquiring data astrophysical observations, they must be kept operating condition, also called “science mode,” that is, a state requires highest possible duty-cycle instrumental parts controls. We report development...
Over the course of a two-week period, starting on Christmas Eve 2003, recently upgraded AURIGA and LIGO observatory were simultaneously acquiring data.This first coincidence run between two projects triggered new collaborative effort in search for gravitational wave bursts.This paper introduces goals AURIGA-LIGO joint analysis methods that have been formulated to address challenges detectors with different spectral sensitivities, bandwidths antenna patterns.Two approaches are presented, both...
We report on a detailed characterization of the conversion efficiency from 1064 nm to second harmonic continuous wave laser light with periodically poled potassium titanyl phosphate crystal, aim building very efficient pump for squeezer Advanced Virgo gravitational interferometric detector. Firstly, we study crystal in double-pass configuration at both fundamental and frequencies. discuss how beam alignment mode hopping affect generation (SHG) performance give map phenomenon our source....
We discuss the new concept of a sensitive and wide-band detector, consisting solid sphere nested inside hollow one: dual sphere.The advantage is that it would be possible to keep both omni-directionality high sensitivity spherical geometry without giving up wide band.In few kHz range complementary 'advanced' interferometers.We also main technological scientific challenges construction such system poses, particularly regarding material choice, fabrication, cooling, suspension readout.
In order to detect gravitational wave signals with resonant bar detectors using Wiener–Kolmogorov (WK) filters, both a model for the power spectrum density (PSD) of noise and signal template should be provided. As analysis is not meant handle non-gaussian data, we have discriminate (and constrain to) time periods where follows quasi-stationary gaussian model. Within these periods, candidate events are selected in WK filter output, their fundamental parameters (time arrival amplitude)...