Since this mathematical technique is not yet a familiar tool in the field of astrophysics, a summary of the fundamental ideas of differential geometry, ergodic theory and catastrophe theory is presented. Such a unified approach facilitates the study of a wide range of, at first sight, very different phenomena within the same physical framework, thus revealing their universal underlying properties.

Advances made by physicists in understanding matter, space, and time and by astronomers in understanding the universe as a whole have closely intertwined the question being asked about the universe at its two extremesâ€"the very large and the very small. This report identifies 11 key questions that have a good chance to be answered in the next decade. It urges that a new research strategy be created that brings to bear the techniques of both astronomy and sub-atomic physics in a cross-disciplinary way to address these questions. The report presents seven recommendations to facilitate the necessary research and development coordination. These recommendations identify key priorities for future scientific projects critical for realizing these scientific opportunities.

Physics at the beginning of the twenty-first century has reached new levels of accomplishment and impact in a society and nation that are changing rapidly. Accomplishments have led us into the information age and fueled broad technological and economic development. The pace of discovery is quickening and stronger links with other fields such as the biological sciences are being developed. The intellectual reach has never been greater, and the questions being asked are more ambitious than ever before. Physics in a New Era is the final report of the NRC's six-volume decadal physics survey. The book reviews the frontiers of physics research, examines the role of physics in our society, and makes recommendations designed to strengthen physics and its ability to serve important needs such as national security, the economy, information technology, and education.

In 1975 the Marcel Grossmann Meetings were established by Remo Ruffini and Abdus Salam to provide a forum for discussion of recent advances in gravitation, general relativity, and relativistic field theories. In these meetings, which are held once every three years, every aspect of research is emphasized - mathematical foundations, physical predictions, and numerical and experimental investigations. The major objective of these meetings is to facilitate exchange among scientists, so as to deepen our understanding of the structure of space-time and to review the status of both the ground-based and the space-based experiments aimed at testing the theory of gravitation.The Marcel Grossmann Meetings have grown under the guidance of an International Organizing Committee and a large International Coordinating Committee. The first two meetings, MG1 and MG2, were held in Trieste (1975, 1979). A most memorable MG3 (1982) was held in Shanghai and represented the first truly international scientific meeting in China after the so-called Cultural Revolution. Three years later MG4 was held in Rome (1985). It was at MG4 that ';astroparticle physics'; was born.MGIXMM was organized by the International Organizing Committee composed of D Blair, Y Choquet-Bruhat, D Christodoulou, T Damour, J Ehlers, F Everitt, Fang Li Zhi, S Hawking, Y Ne'eman, R Ruffini (chair), H Sato, R Sunyaev, and S Weinberg. Essential to the organization was an International Coordinating Committee of 135 members from scientific institutions of 54 countries. MGIXMM was attended by 997 scientists of 69 nationalities. It took place on 2-8 July 2000 at the University of Rome, Italy. The scientific programs included 60 plenary and review talks, as well as talks in 88 parallel sessions. The three volumes of the proceedings of MGIXMM present a rather authoritative view of relativistic astrophysics, which is becoming one of the priorities in scientific endeavour. The papers appearing in these volumes cover all aspects of gravitation, from mathematical issues to recent observations and experiments. Their intention is to give a complete picture of our current understanding of gravitational theory at the turn of the millennium.The Marcel Grossmann Individual Awards for this meeting were presented to Cecille and Bryce DeWitt, Riccardo Giacconi and Roger Penrose, while the Institutional Award went to the Solvay Institute, accepted on behalf of the Institute by Jacques Solvay and Ilya Prigogine. The acceptance speeches are also included in the proceedings.

Physicists argue from different perspectives for and against the idea of the existence of multiple universes.

This unique volume is a collection of papers on various problems in astrophysics and cosmology ? from planetary motion to the arrow of time ? that are closely linked by the common spirit, technique and methodology of chaos.

This volume contains a series of topical lectures in general relativity, cosmology, astrophysics, and field theory, with contributions from theorists and experimentalists.

This volwne is the proceedings of the third school in particle astrophysics that Schramm and Galeotti have organized at Erice. The focus of thirs third school was the Generation of Cosmological Large-Scale Structure. It was held in November of 1996. The fIrst school in the series was on "Gauge Theory and the Early Universe" in May 1986, the second was on "Dark Matter in the Universe" in May 1988. All three schools have been successful under the auspices of the NATO Advanced Study Institute. This volume is thus the third in the series of the proceedings of these schools. The choice of the topic for this third school was natural, since the problem of generating a large-scale structure has become the most pressing problem in cosmology today. In particular, it is this generation of structure that is the interface between astronomical observations and particle models for the early universe. To date, all models for generating structures inevitably require new fundamental physics beyond the standard, SU x SU X U , model of high energy physics. The 3 2 I seeds for generating structures usually invoke unifIcation physics, and the matter needed to clump and form them seems to require particle properties that have not been seen in laboratories to date.

Advanced technologies in astronomy at various wavelengths have provided us with high resolution and high quality data on the QSO population. This meeting was aimed at understanding the morphology and nature of the host galaxies and environments of QSOs. The invited lectures as well as the contributed and poster papers highlighted the main issues of current research: the stellar and gaseous content of the underlying galaxy; the characterization of the population of companions and the nature of their interaction with the host galaxy; the connection between radio-loud QSO and radio-galaxies, and QSOs and ULIRGs; the evolution with redshift of both the host galaxy and its environment, and the main implications in theories of galaxy formation and evolution. This volume provides a valuable overview and timely update of the exciting and rapidly developing field of QSO hosts and their environments - essential reading for graduate students and researchers.