[en] We calculate the change in energy absorbed and the power spectrum in a coherently driven antenna induced by interaction with gravitational radiation. The coherent driving field prepares the antenna in a correlated state which enhances the sensitivity of the detector as proposed in a recent paper by Weber. (orig.)

[en] We discuss the principle and the fundamental limitations of interferometric gravitational wave antennae. We offer a glimpse of the technical problems which have to be solved in order to reach an adequate sensitivity, and we review the present state of the art

[en] The possible use of a capacitive device to detect gravitational waves is discussed. Special emphasis is put on the detection of permanent periodic sources. The intrinsic properties of such a method, its sensitivity, directionality and its wide frequency band, makes it a very appealing one

[en] The RareNoise project investigates non-equilibrium effects in gravitational wave detectors. We illustrate the physics behind the project and the planned project development, involving experimental, numerical and theoretical research.

[en] We describe a Laser Gravitational-wave Antenna in Geodic Orbit design called LAGRANGE that maintains all important LISA science at about half the cost of the original LISA mission and with reduced technical risk. It consists of 3 drag-free spacecraft (SC) in a geocentric formation. Fixed antennas allow continuous contact with the Earth, solving the problem of communications bandwidth and latency. A 70 mm diameter sphere with a 35 mm gap to its enclosure serves as the single inertial reference per SC, operating in 'true' drag-free mode (no test mass forcing). Other advantages are: a single caging design based on the DISCOS 1972 drag-free mission, an all optical read-out with pm fine and nm coarse sensors, and the extreme technology heritage from the Honeywell gyroscopes, and the DISCOS and Gravity Probe B drag-free sensors. An interferometric Measurement System, designed with reflective optics and a highly stabilized frequency standard, performs the ranging between test masses and requires a single optical bench with one laser per SC. Two 20 cm diameter telescope per SC, each with infield pointing, incorporate novel technology developed for advanced optical systems by Lockheed Martin, who also designed the SC based on a multi-flight proven bus structure. Additional technological advancements include include updated propulsion technology, improved thermal control, and a UV-LED charge management system. LAGRANGE subsystems are designed to be scalable and modular, making them interchangeable with those of LISA or other gravitational science missions. We plan to space qualify critical technologies on small and nano satellite flights, with the first launch (UV-LED Sat) in 2013. We further propose a relaxed performance version of LAGRANGE to be flown before 2020 at one quarter the cost of LISA. The requirements on the drag-free sensors and interferometers are relaxed by factors of 10-100 while the core science, super massive black hole (MBH) mergers, is maintained. (authors)

[en] We discuss the limitations placed upon the sensitivity of laser-interferometric gravitational-wave detectors by imperfections in the shape or alignment of the optics, for various different detector configurations. Wave-front distortion is seen to be a serious problem for interferometers which recycle only the light power. We suggest that the use of dual recycling can confer greater tolerance of distortion, and therefore better gravitational-wave sensitivity, upon an interferometer. This suggestion is backed up with results from an experimental implementation of dual recycling. However, in its simple form, dual recycling only helps significantly when the signal bandwidth is narrowed. We propose a new optical arrangement, dual recycling with a compound mirror, which gives greater tolerance of distortion without restricting the bandwidth. This may improve the sensitivity of future gravitational-wave detectors by a factor as high as 5, while at the same time improving their operational flexibility

[en] The research being performed at the University of Rome on transducers concerns two different kinds of resonant transducers: a capacitive transducer coupled to a low noise cooled FET amplifier and an inductive superconducting transducer coupled to a DC SQUID. Both types of transducer are briefly described. (Auth.)

[en] A description of the NAUTILUS gravitational wave detector in operation at Laboratori Nazionali di Frascati of INFN is given. (author)

[en] Triple coincidences between the gravitational wave (GW) antennes in Rome and Maryland and events in the LSD neutrino detector, spread over ∼2 hours on Feb. 23^rd, 1987, have been recently reported to have a probability ∼10^-6 of being accidental. For these coincidences to be signals from SN1987A, the death of the star must be surprisingly long and convulsive, and the energy carried away by neutrinos (gravitational waves) must be two (six) orders of magnitude bigger then expected. The worst of the above obstacles (the factor 10⁶ in GW-antenne response) may be overcome if nearly massless scalar particles do exist, coupled to matter much more weakly than gravitons: their monopole emission and absorption may compensate for their relatively small coupling. The remaining obstacles might also demand brave assumptions that one would be loath to make prior to a confirmation of the effect in the form of coincidences with other neutrino detectors. Maybe the solution to the conundrum is to remove the supernova from the title

[en] A brief survey of peculiarities of physical processes, used in the development of a gravitational radiator and a gravitational detector, is presented. The methods of radiation of gravitational waves under laboratory conditions are conventionally divided into two classes: radiators with spontaneous generation of gravitational waves and those of a parametric type. Some propositions on reception techniques of gravitational waves are considered. As applied to the problem solution of development of the radiator+detector laboratory gravitational scheme great hopes concerning the detector design are related to the mechanism of wave transformation. 10 refs