Contents:Lectures on Algebraic Quantum Field Theory (J Roberts)Introduction to the Algebraic Theory of Superselection Sectors (D Kastler, M Mebkhout & K H Rehren)Localisability of Particle States (K Fredenhagen)Local Observables and the Structure of Quantum Field Theory (S Doplicher)Braid Group Statistics and Their Superselection Rules (K H Rehren)Principles of General Quantum Field Theory Versus New Intuition from Model Studies. An Essay on the Work of J A Swieca (B Schroer)Endomorphisms and Quantum Symmetry of the Conformal Ising Model (G Mack & V Schomerus)Superselection Sectors in Quantum Field Model: Kinks in Φ24 and Charged States in Lattice Q.E.D. (J Fröelich & P A Marchetti)Braid Statistics in 3-Dimensional Local Quantum Theory (J Fröelich, & F Gabbiani)Index Theory of Subfactors and Braid Group statistics (R Longo)Technical Properties of the Quasi-local Algebra (C D'Antoni)Localized Automorphisms of the U(1)-Current Algebra on the Circle. A Simple Example (D Buchholz, G Mack & I Todorov) Readership: High energy physicists, solid state physicists, mathematical physicists and mathematicians.

The interaction between geometry and theoretical physics has often been very fruitful. A highlight in this century was Einstein's creation of the theory of general relativity. Equally impressive was the recognition, starting from the work of Yang and Mills and culminating in the Weinberg-Salam theory of the electroweak interaction and quantum chromodynamics, that the fundamental interactions of elementary particles are governed by gauge fields, which in ma thematical terms are connections in principal fibre bundles. Theoretical physi cists became increasingly aware of the fact that the use of modern mathematical methods may be necessary in the treatment of problems of physical interest. Since some of these topics are covered at most summarily in the usual curricu lum, there is a need for extra-curricular efforts to provide an opportunity for learning these techniques and their physical applications. In this context we arranged a meeting at the Physikzentrum Bad Ronnef 12-16 February 1990 on the subject "Geometry and Theoretical Physics", in the series of physics schools organized by the German Physical Society. The participants were graduate students from German universities and research institutes. Since the meeting occurred only a short time after freedom of travel between East and West Germany became a reality, this was for many from the East the first opportunity to attend a scientific meeting in the West, and for many from the West the first chance to become personally acquainted with colleagues from the East.

Quantum field theory is an area of wide and growing interest to students and researchers of both mathematics and physics. This text is an introduction to the subject which uses mathematical theory of operator algebras to present the theory.

Noncommutative Geometry is one of the most deep and vital research subjects of present-day Mathematics. Its development, mainly due to Alain Connes, is providing an increasing number of applications and deeper insights for instance in Foliations, K-Theory, Index Theory, Number Theory but also in Quantum Physics of elementary particles. The purpose of the Summer School in Martina Franca was to offer a fresh invitation to the subject and closely related topics; the contributions in this volume include the four main lectures, cover advanced developments and are delivered by prominent specialists.

Soon after the discovery of quantum mechanics, group theoretical methods were used extensively in order to exploit rotational symmetry and classify atomic spectra. And until recently it was thought that symmetries in quantum mechanics should be groups. But it is not so. There are more general algebras, equipped with suitable structure, which admit a perfectly conventional interpretation as a symmetry of a quantum mechanical system. In any case, a "trivial representation" of the algebra is defined, and a tensor product of representations. But in contrast with groups, this tensor product needs to be neither commutative nor associative. Quantum groups are special cases, in which associativity is preserved. The exploitation of such "Quantum Symmetries" was a central theme at the Ad vanced Study Institute. Introductory lectures were presented to familiarize the participants with the al gebras which can appear as symmetries and with their properties. Some models of local field theories were discussed in detail which have some such symmetries, in par ticular conformal field theories and their perturbations. Lattice models provide many examples of quantum theories with quantum symmetries. They were also covered at the school. Finally, the symmetries which are the cause of the solubility of inte grable models are also quantum symmetries of this kind. Some such models and their nonlocal conserved currents were discussed.

Recent Advances in Field Theory presents the proceedings of the Fourth Annecy Meeting on Theoretical Physics, held in Annecy-le-Vieux, France, on March 5–9, 1990. This book presents several relevant developments on the subject, including quantum algebra, two-dimensional quantum gravity, and topological quantum theories. Organized into 29 chapters, this book begins with an overview of the Hamiltonian quantization of the topological Chern–Simons theory. This text then examines the conformal affine Liouville model. Other chapters consider the global analyticity properties of functions correlated with causal kernels on de Sitter space. This book discusses as well the three particle models in terms of noncommutative gauge theory, namely, the Peccei-Quinn model, the Glashow–Weinberg–Salam model, and the standard model. The final chapter deals with the development on the construction of lattice integrable models corresponding to the SU (N) coset conformal field theories. This book is a valuable resource for physicists and scientists.