Modem dynamics is increasingly participating in the solution of problems raised by as tronomical observations. This new relationship is being fostered on one side by the im provements in the observations, which in recent years contributed several discoveries of new systems, such as the objects in the Kuiper belt, the pulsar and star companions, to speak only of the most striking ones, and, on the other hand, by the progresses in modem dynamics. The progresses in modem dynamics are due to two factors: the dissemination of fast computers, allowing the numerical studies of very complex systems by a large number of scientists, and the improvement in our understanding of the complex behaviour of Hamiltonian systems. KAM and Nekhorochev theories have shed a light on the subtle and surprizing interplays between regular and chaotic motions; numerical experiments and analytical approximations have shown how these peculiarities are indeed present in astronomically important systems and are instrumental in understanding their formation and evolution.

This book contains essays in honour of Claus Weddepohl who, after 22 years, is retiring as professor of mathematical economics at the Department of Quantitative Economics of the University of Amsterdam. Claus Weddepohl may be viewed as th~ first Dutch mathematical economist in the general equi librium tradition of Arrow, Debreu and Hahn. The essays in this book are centered around the themes Equilibrium, Markets and Dynamics, that have been at the heart of Weddepohl's work on mathematical economics for more than three decades. The essays have been classified according to these three themes. Admittedly such a classification always is somewhat arbitrary, and most essays would in fact fit into two or even all three themes. The essays have been written by international as well as Dutch friends and colleagues including Weddepohl's former Ph. D. students. The book starts with a review of Claus Weddepohl's work by Roald Ramer, who has been working with him in Amsterdam for all those years. The review describes how Weddepohl became fascinated by general equilibrium theory in the early stages of his career, how he has been working on the theory of markets throughout his career, and how he turned to applications of nonlinear dynamics to price adjustment processes in a later stage of his career. The first part of the book, Equilibrium, collects essays with general equilib rium theory as the main theme.

At the opening of the "Third Meeting on Celestial Mechanics - CELMEC III", strong sensations hit our minds. The conference (18-22 June 2001) was being held in Villa Mondragone, a beautiful complex of buildings and gardens located within the township of Monte Porzio Catone, on the hills surrounding Rome. A former papal residence, the building has been recently restored by the University of Rome "Tor Vergata" to host academic activities and events. The conference room is called "Salone degli Svizzeri": here, Gregory XIII, on February 24, 1582, gave its sanction to the reform of the Julian calendar and declared officially in use the calendar still adopted nowadays. The magnificent high walls and tall ceiling strongly resounded, giving to our voice a peculiar Vatican sound, which took us by surprise. May be - we thought - a distant echo of the very words of Gregory XIII proclaiming the modem calendar was still haunting the room. Around us, in the audience, many countries were represented, thus indicating that the idea of putting together the three "souls" of modem Celestial Mechanics - perturbation theories, solar and stellar system studies, spaceflight dynamic- had been successful. CELMEC III is in fact the latest of a series of meetings (the first two editions took place in 1993 and 1997 in L' Aquila, Italy) whose aim is to establish a common ground among people working in Celestial Mechanics, yet belonging to different institutions such as universities, astronomical observatories, research institutes, space agencies and industries.

Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 31 contains literature published in 1982 and received before July 15, 1982; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English .

Presents a unifying approach to the physics of chaos, nonlinear systems, dynamic networks, evolutionary dynamics, econophysics, and the theory of relativity. Each chapter has many worked examples and simple computer simulations that allow the student to explore the rich phenomena of nonlinear physics.

This book is a direct sequel to: B. Bcrtotri and P. Farinclla, "Physics of the Earth and the Solar System, Dynamics and Evolution. Space Navigation. Spa cc-Time Structure" (Kluwcr Academic Publishers, 1990). Nearly 15 years af tcr its publication it became evident that the volume was in need of a new edition to keep up with the outstanding progress and the changing perspectives in this field. David Vokrouhlicky agreed to collaborate on the project and be the third author. On March 25, 2000. after a tong illness and a heart transplant. Paolo Farinella passed away. We then decided that. rather than aiming at a second edition, it made more sense to rewrite the book anew. While its basic content and the structure of the chapters are the same, important new topics have been added, including the extrasolar planetary systems, transneptunian objects. accurate determination of reference frames and new space projects. Greater relevance has been given to scmiquantitarive discussions before intro ducing formal developments: many figures have been added and updated and several errors corrected. More emphasis has given to the solar system, whereas geophysical topics have been left at a less advanced level. To mark this change the slightly differ ent title "Physics of the Solar System" was chosen. We wish to dedicate this book to the memory of Paolo Farinella. an out standing scientist, an invaluable collaborator and a dear friend.