Observational Tests Of Cosmological Inflation

This book represents the proceedings from the NATO sponsored Advanced Research Workshop entitled "Observational Tests of Inflation" held at the University of Durham, England on the 10th-14th December, 1990. In recent years, the cosmological inflation model has drawn together the worlds of particle physics, theoretical cosmology and observational astronomy. The aim of the workshop was to bring together experts in all of these fields to discuss the current status of the inflation theory and its observational predictions. The simplest inflation model makes clear predictions which are testable by astronomical observation. Foremost is the prediction that the cosmological density parameter, no, should have a value negligibly different from the critical, Einstein-de Sitter value of 00=1. The other main prediction is that the spectrum of primordial density fluctuations should be Gaussian and take the Harrison-Zeldovich form. The prediction that n =l, in patticular, leads to several important consequences o for cosmology. Firstly, there is the apparent contradiction with the limits on baryon density from Big Bang nucleosynthesis which has led to the common conjecture that weakly interacting particles rather than baryons may form the dominant mass constituent of the Universe. Secondly, with n =l, the age of the Universe is uncomfortably short if o the Hubble constant and the ages of the oldest star clusters lie within their currently believed limits.

Some 25 years after the birth of inflationary cosmology, this volume sets out to provide both an authoritative and pedagogical introduction and review of the current state of the field. Readers learn about the arguments supporting the many different scenarios of cosmic inflation. Articles are written by eminent scientists, many of whom have made pioneering contributions to the field of inflationary cosmology.

Scientific Cosmology is clearly one of the most active physics research fields at present, and likely to remain so in the near future. Shortly after the pioneering cosmological work of Einstein, Georges Lemaitre proposed a model which some years later to be known as the big-bang model. In the early fifties an alternative proposal, the so called steady-state (expansion at constant density) model, became the fashionable model in prominent academic circles. The discovery of the cosmic background microwave radiation (Penzias & Wilson, 1965) made the steady-state model almost untenable. A quarter of a century later the inflationary model was proposed, becoming extraordinarily popular almost immediately. For some it seemed to combine attractive features of both the steady-state and the big-bang models, by postulating a very early violent (constant density) expansion during a very tiny fraction of a second. The book makes use of the best and most recent observational data, from the Cosmic Background Explorer (COBE, 1992) to the Microwave Anisotropy Probe (WMAP, 2003), to discuss the merits and demerits of inflationary cosmology for a general readership acquainted with the basic facts of scientific cosmology. A complete Glossary and a detailed Index help the reader to follow controversial topics, such as dark matter, dark energy, cosmic flatness and accelerated expansion.

A thorough and up-to-date graduate textbook on the most promising theory of the universe - inflationary cosmology.

Some 25 years after the birth of inflationary cosmology, this volume sets out to provide both an authoritative and pedagogical introduction and review of the current state of the field. Readers learn about the arguments supporting the many different scenarios of cosmic inflation. Articles are written by eminent scientists, many of whom have made pioneering contributions to the field of inflationary cosmology.

Halpern's journey leads us through the most extraordinary breakthroughs in twentieth-century physics and cosmology, and to the remarkable tools scientists employ to look backward and forward in time. He also reveals the fascinating pieces of the puzzle still missing from our picture of the universe - keys that promise to unlock our elusive destiny. What is dark matter and how much of our universe does it comprise? What is the size and age of the universe? How did events unfold in the critical seconds after the Big Bang? The answers to these and other questions will help us decipher our fate.

This thesis explores the idea that the Higgs boson of the Standard Model and the cosmological inflation are just two manifestations of one and the same scalar field - the Higgs-inflation. By this unification two energy scales that are separated by many orders of magnitude are connected, thereby building a bridge between particle physics and cosmology. An essential ingredient for making this model consistent with observational data is a strong non-minimal coupling to gravity. Predictions for the value of the Higgs mass as well as for cosmological parameters are derived, and can be tested by future experiments. The results become especially exciting in the light of the recently announced discovery of the Higgs boson. The model of non-minimal Higgs inflation is also used in a quantum cosmological context to predict initial conditions for inflation. These results can in turn be tested by the detection of primordial gravitational waves. The presentation includes all introductory material about cosmology and the Standard Model that is essential for the further understanding. It also provides an introduction to the mathematical methods used to calculate the effective action by heat kernel methods.

Inflation has revolutionized cosmology primarily because it has eliminated the dependence of cosmological modelling on initial conditions. Thus inflationary cosmology is able to account for the present universe starting from a wide range of initial conditions. This volume reviews the presents state of subject. Each chapter consists of a brief introduction followed by reprints of important papers. Experts in the field are also provided with a unifying view point.