Large Scale Structure In The Universe Proceedings Of The International Workshop

This volume documents the theoretical and observational results and arguments in favour of (or against) the most preferred models of structure formation. New observational results of the large scale distribution of matter are confronted with recent theories on the origin and evolution of structure in the universe.

Proceedings of the 130th Symposium of the International Astronomical Union, dedicated to the memory of Marc A. Aaronson (1950-1987), held in Balatonfured, Hungary, June 15-20, 1987

The 1980's have been times of great excitement in Astrophysics and Cosmology. Professors Dennis Sciama and Fabio Mardirossian and all the other Members of the Organizing Committees are to be congratulated for having given us a taste of this excitement in Trieste, by inviting the leaders of the subject to the meeting they have organized. The excitement has corne from the new observations of the three-dimensional structure of the universe through a large number of new measurements of redshifts. These have revealed that clusters of galaxies are distributed on the surface of big empty bubbles of diameters of the order of 20-50 Mpc. Additionally, there is some evidence for invisible dark matter (whose composition is not known) as well as evidence for the gravitational lens effect. To cap this has corne the supernova of 1987, an event which last occurred 383 years ago. For the first time in history, the neutrino flux from the supernova was measured, giving limits to neutrino masses and numbers of neutrino types. (The dark matter problem is related to Particle Physics - beyond this standard model). It is good to be alive when all this happens and to try to comprehend this. Once again, our appreciation to the organisers and to those who presented their beautiful results.

The significance of the present IAU symposium, "The Large Scale Structure of the Universe", fortunately requires no elaboration by the editors. The quality of the wide range of observational and theoretical astrophysics contained in this volume speaks for itself. The published version of the proceedings contains all the contributions presented at the symposium with the exception of the introductory lecture by V. A. Ambartsumian. Contributed papers, short contributions and discussions have been included according to the recommendations of the IAU. Many people contributed to the success of the symposium. First of all, thanks are due to the USSR Academy of Sciences and to the Estonian Academy of Sciences for sponsoring this symposium in Tallinn. The efforts of Academician K. Rebane, President of the Estonian Academy of Sciences, are particularly appreciated. The astronomical hosts of the symposium were the members of the W. Struve Astrophysical Observatory of Tartu who made outstanding efforts to lavish participants with Estonian hospitality which was greatly appreciated and enjoyed by them and their guests. The members of the Scientific and Local Organising Committees are listed below and we thank all of them for their contributions which were central to the success of the symposium. In addition are listed members of the Technical Organising Committee who were responsible for all details of the organisation and whose vigilance ensured that all aspects of the symposium ran smoothly and efficiently. Their contributions are all gratefully acknowledged.

Understanding the largest physical structures in the universe is essential for the comprehension of the cosmos as a whole. We want to know how our world is formed, what it is made of and how it evolves.Galaxies, as the most visible constituents of the universe, are interesting probes for the cosmic time sequence. Their formation and development provides us with unique clues to the cosmic evolution. This is tightly connected with the hierarchical cosmic structure: groups and clusters of galaxies and their embedding into the large scale structure offer the opportunity to study the dependencies.Galaxy redshift surveys delineate most impressively a large cosmic web, which is composed of sheets and filaments. Grand simulations of the cosmic evolution complement these observations from the theoretical side and allow one quantify and compare various model universes.Quasar absorption line studies, gravitational lensing and even the X-ray background radiation provide important quantitative measures of the history of matter clustering. Finally, the microwave radiation traces very early structures, which are supposed to originate in the phase of inflationary expansion shortly after the big bang.This volume constituting the proceedings of the 12th Potsdam Cosmology Workshop, deals with the basic aspects of cosmological structure formation on the largest physical scales.

Ten years ago in August 1977 Malcom Longair and Jan Einasto organized IAU Symposium nO 79 on exactly the same exciting and most important topic i.e. the Large Scale Structure of the Universe. Many of us have the recollection of an outstanding meeting which fulfilled two goals (i) establish most of the foundation of a fast growing field (ii) set up a confrontation between the excellent observational and theoretical work performed in eastern and western countries. A decade after such a meeting Alex Szalay and I have felt the need to reassemble the cosmologists working actively on problems dealing with the Uni verse as a whole. Indeed a lot of progress has been achieved in the building of large surveys in the discovery of voids, sponges and filaments in the galaxy clus ter distribution, in refined numerical simulations, in experimental and theoretical particle physics (outcome of new particles (cold particles) and unification (GUT, supersymmetry) schemes), in research of quantum gravity and inflation scenarios etc ... A new confrontation between all the specialists working all throughout the world on such questions appeared to us to be most timely. This is why the location of Balatonfiired in Hungary to be accessible to anyone as Tallin in 1977 has been chosen.

Ten years ago in August 1977 Malcom Longair and Jan Einasto organized IAU Symposium nO 79 on exactly the same exciting and most important topic i.e. the Large Scale Structure of the Universe. Many of us have the recollection of an outstanding meeting which fulfilled two goals (i) establish most of the foundation of a fast growing field (ii) set up a confrontation between the excellent observational and theoretical work performed in eastern and western countries. A decade after such a meeting Alex Szalay and I have felt the need to reassemble the cosmologists working actively on problems dealing with the Uni verse as a whole. Indeed a lot of progress has been achieved in the building of large surveys in the discovery of voids, sponges and filaments in the galaxy clus ter distribution, in refined numerical simulations, in experimental and theoretical particle physics (outcome of new particles (cold particles) and unification (GUT, supersymmetry) schemes), in research of quantum gravity and inflation scenarios etc ... A new confrontation between all the specialists working all throughout the world on such questions appeared to us to be most timely. This is why the location of Balatonfiired in Hungary to be accessible to anyone as Tallin in 1977 has been chosen.