In the last few years there has been a revival of interest in the old idea that spacetime may have more than four dimensions, all but four having been curled up into a small circumference. In this view the various particles and interactions we see at ordinary energies arise from a simple, perhaps purely geometrical, theory in higher dimensions. This idea has profound implications for elementary particle physics and cosmology, and raises challenging problems of mathematics. These matters were the topic of the Second Jerusalem Winter School of Theoretical Physics.

The School explored the delicate interplay between geometry and statistical mechanics in these materials such as microemulsions, wetting and growth interfaces, bulk lyotropic liquid crystals, chalcogenide glasses and sheet polymers, using tools from the fields of polymer physics, of differential geometry and of critical phenomena.

The study of the correlated motion of electrons in solids is of increasing importance in condensed matter physics. In the past few years, the discovery of high-temperature superconductors has stimulated an enormous theoretical effort in this area, building on earlier theories of heavy-fermion and organic superconductors, and magnetic insulators. In a separate development the discovery of the fractional quantum Hall effect stimulated research into the behavior of the two-dimensional electron gas in a strong transverse magnetic field.The lectures at this school gave a systematic presentation of the current status of the theory in these areas. They covered the fractional quantum Hall effect and the many-body physics of the Hubbard model and its extensions, paying particular attention to the properties of doped insulators which are relevant for high-temperature superconductivity. There were detailed discussions of situations for which controlled calculations may be carried out — specifically infinite dimensions, one dimension, and generalized models in which the fermions have N components and N → •.

This unique volume contains a selection of more than 80 of Yuval Ne''eman''s papers, which represent his huge contribution to a large number of aspects of theoretical physics. The works span more than four decades, from unitary symmetry and quarks to questions of complexity in biological systems and evolution of scientific theories. In keeping with the major role Ne''eman has played in theoretical physics over the last 40 years, a collaboration of very distinguished scientists enthusiastically took part in this volume. Their commentary supplies a clear framework and background for appreciating Yuval Ne''eman''s significant discoveries and pioneering contributions. Contents: (Authors of Commentaries in Parentheses): SU(3), Quarks and Symmetry Breaking (Y Verbin); Algebraic Theory of Particle Physics and Spectrum Generating Algebras (N Cabibbo); Supersymmetry and Supergravity (R Kerner); Geometrization of Physics (T Regge); SU(2/1) Super-Unification of the Standard Model and Non Commutative Geometry (J Thierry-Mieg); Spinor Representations of GL ( N, P ) and Chromogravity (I Kirsch); Metric-Affine Gravity (F W Hehl); Strings, Branes and Other Extendons (Dj aijaiki); Various Topics in Astrophysics (J Bahcall); Foundations of Physics (A Botero); Philosophy and Sociology of Science: Evolution and History (J Rosen). Readership: Researchers in physics and mathematical physics, and scientists interested in history of physics and philosophy of science."