The core scientific field of Einstein Telescope (ET) is gravitational wave (GW) physics. GWs are opening a new window on the cosmos that can revolutionize humanity's understanding of the universe up to cosmological distances and unlock unexplored territories of extreme physical conditions that no experiment on Earth can ever provide. ET has the ambitious mission to push the limits of our ability to detect GWs and learn more about the evolution of our Universe back to its earliest form right after the Big Bang. Based on well proven and experimentally tested concepts, ET will exploit cutting-edge technologies and push them to their physical limits. It combines the well-proven technologies from the current advanced LIGO and Virgo detectors with beyond-state-of-the-art systems planned for the next evolution stage of the advanced detectors, in an infrastructure designed to accommodate several technology upgrades over many decades. ET has been included in the ESFRI roadmap 2021.
The main objective of the ET-PP project is to support crucial items in the preparatory phase of the experiment, including: the enlargement of the ET consortium, the legal framework, governance schemes, and financial regulations under which the ET Research Infrastructure will be constructed and operated; the technical design and costing of the ET observatory; the preparation of the site selection, where ET will be deployed, detailing and cost-estimation of the required site infrastructure, and its socio-economic and environmental impacts; the schemes for technology transfer, procurement and industry involvement in the technical design and construction of ET; and the required linking with relevant science communities regarding the detailed definition of the science program, and the user services and data access model.