Topological defects have recently become of great interest in condensed matter physics, particle physics and cosmology. They are the unavoidable remnants of many symmetry breaking phase transitions. Topological defects can play an important role in describing the properties of many condensed matter systems (e.g. superfluids and superconduc tors); they can catalyze many unusual effects in particle physics models and they may be responsible for seeding the density perturbations in the early Universe which de velop into galaxies and the large-scale structure of the Universe. Topological defects are also of great interest in mathematics as nontrivial solutions of nonlinear differential equations stabilized by topological effects. The purpose of the Advanced Study Institute "Formation and Interactions of Topo logical Defects" was to bring together students and practitioners in condensed matter physics, particle physics and cosmology, to give a detailed exposition of the role of topo logical defects in these fields; to explore similarities and differences in the approaches; and to provide a common basis for discussion and future collaborative research on common problems.

Introduction. Phase Transitions in the Early Universe and Defect Formation; T.W.B. Kibble. The Topological Classification of Defects; M. Kleman. Introduction to Growth Kinetics Problems; G.F. Mazenko. Dynamics of Cosmological Phase Transitions: What Can We Learn from Condensed Matter Physics? N. Goldenfeld. Topological Defects and Phase Ordering Dynamics; A.J. Bray. The Production of Strings and Monopoles at Phase Transitions; R.J Rivers, T.S. Evans. Geometry of Defect Scattering; N.S. Manton. Theory of Fluctuating Nonholonomic Fields and Applications: Statistical Mechanics of Vortices and Defects and New Physical Laws in Spaces with Curvature and Torsion; H. Kleinert. String Network Evolution; E.P.S. Shellard. Global Field Dynamics and Cosmological Structure Formation; R. Durrer. Electroweak Baryogenesis; N.G. Turok. Dynamics of Cosmic Strings and Other Brane Models; B. Carter. Cosmological Experiments in Superfluids and Superconductors; W. Zurek. Cosmological Experiments in Liquid 4He-Problems and Prospects; P.C. Hendry et al. Index.