The fourth edition includes new developments, in particular a new section on the double beta decay including a discussion of the possibility of a neutrinoless decay and its implications for the standard model.

I am very happy to accept the translators' invitation to write a few lines of introduction to this book. Of course, there is little need to explain the author. Pauli's first famous work, his article on the theory of relativity in the Encyklopädie der Mathematischen Wissenschaften was written at the age of twenty. He afterwards took part in the development of atomic physics from the still essentially classical picture of Bohr's early work to the true quantum mechanics. Thereafter, some of his work concerned the treatment of problems in the framework of the new theory, especially his paper on the hydrogen atom following the matrix method without recourse to Schrodinger's analytic form of the theory. His greatest achievement, the exclusion principle, generally known today under his own name as the Pauli principle, that governs the quantum theory of all problems including more than one electron, preceded the basic work of Heisenberg and Schrodinger, and brought him the Nobel prize. It includes the mathematical treatment of the spin by means of the now so well known Pauli matrices. In 1929, in a paper with Heisenberg, he laid the foundation of quantum electrodynamics and, in doing so, to the whole theory of quantized wave fields which was to become the via regia of access to elementary particle physics, since here for the first time processes of generation and annihilation of particles could be described for the case of the photons.

The first textbook on this important topic, for graduate students and researchers in particle and condensed matter physics.

The NATO Advanced Study Institute on Quantum Electrodynamics of Strong Fields was held at Lahnstein on the Rhine from 15-26 June, 1981. The school was devoted to the advances, theoretical and exper imental, in the physics of strong fields made during the past decade. The topic of the first week was almost exclusively quantum electrodynamics, with discussions of symmetry breaking in the ground state, of the physics of heavy ion collisions and of precision tests of perturbative quantum electrodynamics. This was followed in the second week by the presentation of a broad range of other areas where strong fields occur, reaching from nuclear physics over quantum chromodynamics to gravitation theory and astrophysics. We were fortunate to be able to call on a body of lecturers who not only have made considerable personal contributions to these advances but who are also noted for their lecturing skills. Their dedication for their subject was readily transmitted to the stu dents resulting in a very successful school. This enthusiasm is also reflected in their contributions to these Proceedings which, as I believe, will in time become a standard source of reference for future work on the physics of strong fields and will help to spread the benefits of the school to a larger audience than those who were able to attend. I regret that the Soviet colleagues Ya. B. Zeldovich and V. S. Popov were unable to participate.

These proceedings are the fourth in the series of International Conferences covering fission and properties of neutron-rich nuclei, which are at the forefront of nuclear structure research. The time interval of 5 years between each conference allows for significant new results to be achieved. Recently, world leaders in theory and experiments in research and the development of new facilities for research presented their latest results in areas such as synthesis of superheavy elements, new facilities for and recent results with radioactive ion beams, structure of neutron-rich nuclei, nuclear fission process, fission yields and nuclear astrophysics. This book is a major source of the latest research in these areas and plans for the future. The conference brought together a unique group of over 100 speakers including the directors of the major nuclear laboratories in Canada, France, Germany, Japan, Russia and the US along with leading research scientists from around the world.

These proceedings are the fourth in the series of International Conferences covering fission and properties of neutron-rich nuclei, which are at the forefront of nuclear structure research. The time interval of 5 years between each conference allows for significant new results to be achieved. Recently, world leaders in theory and experiments in research and the development of new facilities for research presented their latest results in areas such as synthesis of superheavy elements, new facilities for and recent results with radioactive ion beams, structure of neutron-rich nuclei, nuclear fission process, fission yields and nuclear astrophysics. This book is a major source of the latest research in these areas and plans for the future. The conference brought together a unique group of over 100 speakers including the directors of the major nuclear laboratories in Canada, France, Germany, Japan, Russia and the US along with leading research scientists from around the world.