Final Report Summary - ELITES (ET-LCGT Telescopes: Exchange of Scientists) The ELiTES project aimed to set common basis for the development of future gravitational wave detectors in Europe and in Japan. In 2011, when ELITES has been thought, gravitational wave research was a promising sector of the research in astrophysics and a new (2nd) generation of gravitational wave detectors was under construction in Europe (Advanced Virgo) and USA (Advanced LIGO). Furthermore, the design study of a 3rd generation gravitational wave observatory, the Einstein Telescope (ET), funded by the European Commission through a FP7 project, was just delivered and in Japan the idea of a future gravitational wave detector, LCGT, was defined in a solid project. ELiTES has been thought to develop synergies between the common ideas of ET and LCGT through joint technological developments and exchange of know-how. The global scenario since the beginning of this decade is totally and positively evolved: • the LCGT project becomes a reality through the construction of a 3km long, underground and cryogenic detector in Japan: KAGRA• the 3G idea pioneered by ET is now a concept worldwide accepted and a global coordination effort, involving, at least, European, American and Australian scientists is currently proceeding. • And, the most important ingredient, the detection of gravitational wave has been achieved in the LIGO detectors and announced by the LIGO and Virgo collaborations the 11th of February 2016. The detection of the gravitational wave signal emitted by the coalescence of two black holes has been a monumental discovery and the beginning of a new era: the gravitational wave astronomy.Obviously ELiTES has been a small project in this global scenario, but it had a catalysing role; ELiTES shown that it is possible to have a trans-continental approach in the design of future (3G) observatories; it pioneered the studies on cryogenics in gravitational wave interferometric detectors and faced, thanks to the KAGRA experience, the difficulties of the realisation of an underground research infrastructure. European scientists seconded in Japan contributed to the design and prototypal realisation of the cryogenic suspension of the KAGRA detector, one of the most difficult and challenging components of KAGRA. New assembling technology, like the silicate bonding and Indium bonding, have been introduced in KAGRA by European groups and European scientists entered in the KAGRA scientific collaboration. European companies realised components for the KAGRA detector. Thermal noise issues have been studied together, evaluating the behaviour of optical materials and components at cryogenic temperature. New optical component studies, like the long filter cavities for future optical squeezing designs, have been initiated in ELiTES. The Japanes know-how in the realisation of low noise cryo-cooler and in the realisation of underground infrastructures for gravitational detectors has been transmitted to the ELiTES teams. Five general meetings have been organised by ELiTES in Tokyo, hosted by the European Delegation in Japan (and by a Japanese university). This has been a key element for the success of the dissemination and outreaching activities in ELiTES. The ELiTES meetings have been open to Japanese schools and cultural institutions; members of the Japanese University and Research Ministry (MEXT) participated to some of them; a public lecture of the Nobel prize laureate member of ELiTES, prof. Takaaki Kajita, was organised in the last ELiTES meeting, scientific delegates of the European Embassies in Japan participated to our meetings. In addition, we organised an Italy-Japan bilateral meeting hosted by the Italian Institute of culture and ELiTES representatives (M. Punturo and K. Kuroda) have been invited to present ELiTES as example of successful Europe-Japan collaboration during the presentation of the Horizon 2020 programme in Tokyo. Last but not least, ELiTES stimulated the funding by the MEXT for a symmetric programme of secondment of Japanese scientists in Europe, through the so-called core-to-core programme. ELiTES plaid a role also in the training of young researchers through the organisation in the Jena University (Germany) of training sessions devoted to thermal noise issues in gravitational wave detectors; European and Japanese young researchers, members of ELiTES, participated to these activities.
