In this volume a wide range of topics in particle physics, string theory and cosmology and their interconnections is covered.

In this volume a wide range of topics in particle physics, string theory and cosmology and their interconnections is covered.

This book contains papers by leading physicists on developments in high energy physics, string theory and cosmology. Topics covered include recent results from accelerator and non-accelerator experiments, CP-violation, neutrino physics, precision tests of the Standard Model, quantum gravity and two-dimensional gravity, superstring theory and superstring phenomenology, relativistic astrophysics and cosmology.

PASCOS is an interdisciplinary symposium on the interface of of Particle physics, String theory and Cosmology. Over the past two decades these three disciplines have increasingly become closer. Historically there was always a strong overlap between particle physics and cosmology. This connection has become even stronger with the realization that some of the fundamental issues in cosmology such as the presence of dark matter and dark energy may possibly find a resolution only via new theories of particle physics. At the same time string theory has begun to play an increasingly important role in particle physics as a possible framework for building unified models of particle interaction including gravity. In recent years we have seen an increasing overlap between cosmology and string theory and currently the area of string cosmology is one of the most active fields of research. PASCOS 2005 aimed to provide coherent discussions of recent developments on the interface of the three disciplines and also on their interconnections. In particular, superstring aspects in low energy particle theory (SUSY) and cosmological applications (moduli stabilization) are extensively covered in this volume. Topics include dark matter and dark energy, baryogenesis, flavor and CP violation, neutrino physics, supersymmetry and extra dimensions, flux compactification, string model building, as well as brane cosmology.

The PASCOS (International Symposium on Particles, Strings and Cosmology) series brings together the leading experts and most active young researchers in the closely related fields of elementary particle physics, string theory and cosmology/astrophysics. These areas of research have become increasingly intertwined in recent years, each having direct impact on the others. In particular, there has been a dramatic expansion of ideas from particle theory and string theory that have vast impact on cosmology, especially our picture of the early universe and its evolution. Correspondingly, the proliferation of data regarding the early universe, and its increasing precision, has begun to strongly constrain the theoretical models. Meanwhile, observations of neutrino oscillations and cosmic ray excesses, and limits on new physics from colliders and other particle experiments, as well as the resulting restrictions on theoretical and phenomenological modeling, are becoming ever stronger. During PASCOS99, it became clear that the long-awaited era of convergence of these fields is truly at hand.The proceedings of PASCOS 99 reflect the accelerating overlap and convergence of the fields of elementary particles physics, string theory and cosmology/astrophysics. Plenary reviews by leading figures in these fields provide perspectives on these interrelationships and up-to-the-minute summaries of recent progress in the various areas. Parallel talk summaries focus on many of the topics within each field of greatest current interest and activity. Both the plenary and parallel writeups are designed to be descriptive in nature and avoid being overly technical. As a result, the volume can serve as a useful reference for students and professionals in all three fields. Careful referencing allows further pursuit of a given topic. Overall, the proceedings are unique in that they not only bring together in a single volume comprehensive overview of the great progress being made in all three of these very exciting fields, but also provide a snapshot of how particles, strings and cosmology are increasingly impacting one another.

String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects called strings, rather than the zero-dimensional point particles that form the basis for the standard model of particle physics. The phrase is often used as shorthand for Superstring theory, as well as related theories such as M-theory. By replacing the point-like particles with strings, an apparently consistent quantum theory of gravity emerges. Moreover, it may be possible to 'unify' the known natural forces (gravitational, electromagnetic, weak nuclear and strong nuclear) by describing them with the same set of equations. Studies of string theory have revealed that it predicts higher-dimensional objects called branes. String theory strongly suggests the existence of ten or eleven (in M-theory) space-time dimensions, as opposed to the usual four (three spatial and one temporal) used in relativity theory.