Einstein Telescope

LAPP’s Gravitational Waves group has become progressively more involved in the preparations for the future gravitational wave detector, the Einstein Telescope (ET). ET (and its counterpart Cosmic Explorer in the United States) is intended to follow on from the ground-based detectors Virgo, LIGO and KAGRA, and will operate on the same principle. It is planned to be installed underground, where seismic noise is weaker than on the surface, in order to open up the bandwidth to low frequencies. ET should improve sensitivity by more than an order of magnitude compared with current detectors (see ET_2), enabling us to observe a volume of the universe more than 1000 times larger. With this level of sensitivity, ET will be able to observe all the black hole coalescences in the Universe and a very large fraction of neutron star coalescences. ET will thus shed unique light on the theory of gravity and on the evolution of the Universe.

The detector consists of two types of interferometer: the first is dedicated to the detection of high-frequency gravitational wave signals (ET_HF) and uses technologies similar to those used in current detectors. The second is dedicated to the detection of low-frequency signals and is based on new technologies (in particular using a longer wavelength) and will operate at cryogenic temperature (10-20K).