The Virgo Experiment is a gravitational wave interferometric detector. It consists in a Michelson interferometer with two 3 km long Fabry‐Perot cavities as orthogonal arms. The installation of the detector has been completed in September 2003 and presently the apparatus is under commissioning. In this article an overview of the detector status is presented

This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. JINST 7 P03012In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency.This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper.

The classical limit of quantum q-oscillators suggests an interpretation of the deformation as a way to introduce non linearity. Guided by this idea, we considered q-fields, the partition fumction, and compute a consequence on specific heat and second order correlation function of the q-oscillator which may serve for experimental checks for the non linearity.

We report on the status of the Virgo detector, under commissioning. We will focus on the last year's activity. The two commissioning runs performed during 2005 allowed us to reach a sensitivity of h ∼ 6 × 10 −22. The data obtained during the runs were used to test a few data analysis algorithms, namely coalescing binaries and burst searches. The main improvements made on the detector during this year will be described, as well as the plans and activities foreseen in the coming years.