The GEO-HF project

This issue is published as the Proceedings of the 6th Edoardo Amaldi Conference on Gravitational Waves, held on 20-24 June 2005 at Bankoku Shinryoukan in Okinawa, Japan. Since the first Amaldi conference was held in Frascati in 1994, eleven years have passed and the scale of the conference has grown with the increasing activity in the field of gravitational waves. As the centenary celebration of Einstein's 'miracle year', 2005 was called 'World Year of Physics'. Among his breakthroughs published in 1905, the special theory of relativity is recognized as the most significant revolution in physics, completely changing our views concerning time and space. Ten years later, Einstein proposed the general theory of relativity, by which he predicted the existence of gravitational waves (GWs). At that time, it was only a dream to observe a GW because its effect was so small. Efforts to detect GWs, pioneered by Weber, have continued for almost 40 years, yet their detection remained a dream. However, the presentations at this conference have convinced us that it is no longer a dream. The GW detector projects have made extraordinary advances; in particular, the significant sensitivity improvement of LIGO and the completion of the VIRGO detector mark the beginning of the new era of GW physics. Firm developments in theories and source estimations were also reported. In particular, the data analysis session was very active and various discussions were held. Elaborate experimental techniques were presented, some of them already achieving the requirements for the next generation of detectors, such as Advanced LIGO and LCGT. In addition to the earth-based detectors, many presentations concerning space detectors were contributed; they indicated that space would become the new stage for GW physics and astronomy. This issue brings together the papers which were presented at this exciting conference. The proceedings comprise two volumes; the largest part is published as a volume of Journal of Physics: Conference Series and the other is a special issue of Classical and Quantum Gravity (CQG), presenting the highlights of the conference. This is the first time this format has been used and selecting the highlights for CQG was a difficult task as the quality of the papers submitted was so high. The issue has been published thanks to the excellent work of the reviewers who gave precise and appropriate comments to the Editors. We strongly believe this issue to be a milestone in the inception of GW astronomy. The conference organizers would like to acknowledge the financial support of IUPAP, Okinawa prefecture, Inoue Foundation for Science, The Foundation for Promotion of Astronomy and a Grant-in-Aid for Scientific Research on Priority Areas (415) of the Ministry of Education, Culture, Sports, Science and Technology. The conference scientific programme was organized with the help of the session conveners. Their collaboration was indispensable for the success of the conference. We also appreciate the members of the international advisory committee and the local organizing committee; in particular, we thank Dr Akiteru Takamori for designing the fascinating poster of the conference and the image for the cover of this issue. The miscellaneous duties that were necessary for the conference were carried out with the help of ICS Convention Design Inc. with special thanks due to Ms Makiko Uwato and Mr Hiroyuki Suzuki. The proceedings are published by Institute of Physics Publishing; we would like to express our deep appreciation to Ms Judith Adams for her efficient management of the proceedings. Finally, we thank all of the excellent participants who made the conference so successful