This volume contains the written versions of the lectures held at the "22 Internationale Universitatswochen fur Kern- physik" in Schladming, Austria, in February 1983. The generous support of the Austrian Federal Ministry of Science and Research, the Styrian Government and other sponsors once again made it possible for expert lecturers to be invited. In choosing the topics, the aim was to achieve a balance between the theoretical and phenomenological contributions; on the theoretical side, discussions centred on the impact of different approaches to quantum field theory on the ele- mentary particle scenario, on the other, on the recent re- sults in high energy physics which have provided fresh moti- vations for new kinds of experiments as well as having had a profound influehce on cosmology. Limited space has made it impossible to include manuscripts of the many interesting seminars presented. The lecture notes were reexamined by the authors after the school and are now published in their final form. It is a pleasure to thank all the lecturers for their efforts, which made it possible to speed up publication. Thanks are also due to Mrs. Neuhold for the careful typing of the notes. H. Mitter C. B. Lang Acta Physica Austriaca, Suppl. XXV, ~70 (1983) @ by Springer-Verlag 1983 THE EARLY UNIVERSE - FACTS AND FICTION+ by G. BaRNER Max-Planck-Institut fUr Physik und Astrcphysik Institut fUr Astrophysik Karl-Schwarzschild-Str. 1 8046 Garching b. MUnchen, FRG 1.