109th Nobel Symposium `Particle Physics and the Universe'
Lars Bergström, P. Carlson, Claes Fransson · Physica Scripta · 2000
It is generally felt in the cosmology and particle astrophysics community that we have just entered an era which later can only be looked back upon as a golden age. Thanks to the rapid technical development, with powerful new telescopes and other detectors taken into operation at an impressive rate, and an accompanying advancement of theoretical ideas, the picture of the past, present and future Universe is getting ever clearer. Some of the most exciting new findings and expected future developments were discussed at the 109th Nobel Symposium `Particle Physics and the Universe'. The meeting took place in the historical setting of Haga Slott, some 100 km west of Stockholm. This is a 16th-century castle which has been transformed into a modern conference site, not least known for its beautiful suuroundings and awarded cuisine. The setting turned out to be ideal for the kind of informal discussions and exchange of ideas which constitute the main purpose of Nobel Symposia. Also the scheduled talks, with ample time for discussions, turned out to be just as stimulating as we could ever have hoped. Certainly, as organizers we were extremely pleased with the Symposium, and we deduce from the many signs of appreciations from the participants that this was a general consensus. It is our firm hope and conviction that this volume, containing the written Proceedings of the Symposium, will convey some of the enthusiasm and intellectual excitement that was so clearly felt on location. We sincerely thank the speakers for contributing such excellent written versions of their contributions to the Symposium. We were deeply shocked to learn about the tragic accidental death of one of our most respected colleagues in the field, David Schramm, some months before the Symposium. In his sadly felt absence, we were grateful to Michael Turner for making a special contribution commemorating some of Schramm's most influential work in cosmology and particle astrophysics. The topics covered at the Symposium, and reported in this volume (with the exception of the talk by B Sadoulet), include the physics of the early Universe (string cosmology, inflation, nucleosynthesis, dark matter relics) and ultra-high energy processes (gamma ray bursts, AGNs, particles above 100 EeV). A particular emphasis is also put on neutrino physics and astrophysics, with the evidence for non-zero neutrino masses emerging from both solar neutrinos and atmospheric neutrinos covered in great depth. Another field with interesting new results concerns the basic cosmological parameters, where both traditional methods and the potential of new ones like deep supernova surveys and acoustic peak detections in the cosmic microwave background are thoroughly discussed. Various aspects of the dark matter problem, such as gravitational lensing estimates of galaxy masses, cluster evolution and hot cluster electron distorsions of the thermal microwave background spectrum are discussed, as are particle physics candidates of dark matter and methods to detect them. Cosmic rays of matter and antimatter are included as a topic as is the problem of the enigmatic dark energy of the vacuum. We want to express our thanks to the Nobel Foundation and its Symposium Committee for funding the Symposium. The staff of Haga Slott were extremely friendly and helpful, and we also wish to thank a number of graduate students in Stockholm, in particular David Bergströ, Mirko Boezio, Edvard Mörtsell and Piero Ullio, for acting as scientific secretaries at the sessions.