This book is written for theoretical and mathematical physicists and mat- maticians interested in recent developments in complex general relativity and their application to classical and quantum gravity. Calculations are presented by paying attention to those details normally omitted in research papers, for pedagogical r- sons. Familiarity with fibre-bundle theory is certainly helpful, but in many cases I only rely on two-spinor calculus and conformally invariant concepts in gravitational physics. The key concepts the book is devoted to are complex manifolds, spinor techniques, conformal gravity, ?-planes, ?-surfaces, Penrose transform, complex 3 1 - - space-time models with non-vanishing torsion, spin- fields and spin- potentials. 2 2 Problems have been inserted at the end, to help the reader to check his und- standing of these topics. Thus, I can find at least four reasons for writing yet another book on spinor and twistor methods in general relativity: (i) to write a textbook useful to - ginning graduate students and research workers, where two-component spinor c- culus is the unifying mathematical language.

The Joint European and National Astronomical Meeting (JENAM) of 2002, was held in Porto - Portugal (2-7 September 2002), corresponding to the I ph Meeting of the European Astronomical Society (EAS) and the IJ! En- contra Nacional de Astronomia e Astroftsica (12ENAA) of the Sociedade Portuguesa de Astronomia (SPA). Portugal has a small and young community of researchers in Astronomy. This meeting have had an important role in marking the beginning of what we expect to be a new phase for Astronomy in Portugal. The fact that we have chosen to address '"the future" reflects this will of the Portuguese com- munity to share and discuss our commitment for the next decades with our colleagues. The meeting, titled "The Unsolved Universe: Challenges for the Fu- ture", aimed at discussing some of the major research programmes and objec- tives for the next decades. The scientific programme included the plenary ses- sions (invited reviews and highlight talks), whose contributions are published in this book, and several workshops on more specific topics.

Soliton theory is an important branch of applied mathematics and mathematical physics. An active and productive field of research, it has important applications in fluid mechanics, nonlinear optics, classical and quantum fields theories etc. This book presents a broad view of soliton theory. It gives an expository survey of the most basic ideas and methods, such as physical background, inverse scattering, Backl nd transformations, finite-dimensional completely integrable systems, symmetry, Kac-moody algebra, solitons and differential geometry, numerical analysis for nonlinear waves, and gravitational solitons. Besides the essential points of the theory, several applications are sketched and some recent developments, partly by the authors and their collaborators, are presented.

This book is a comprehensive reference on differential geometry. It shows that Maxwell, Dirac and Einstein fields, which were originally considered objects of a very different mathematical nature, have representatives as objects of the same mathematical nature. The book also analyzes some foundational issues of relativistic field theories. All calculation procedures are illustrated by many exercises that are solved in detail.

Relativistic quantum electrodynamics, which describes the electromagneticinteractions of electrons and atomic nuclei, provides the basis for modeling the electronic structure of atoms, molecules and solids and of their interactions with photons and other projectiles. The theory underlying the widely used GRASP relativistic atomic structure program, the DARC electron-atom scattering code and the new BERTHA relativistic molecular structure program is presented in depth, together with computational aspects relevant to practical calculations. Along with an understanding of the physics and mathematics, the reader will gain some idea of how to use these programs to predict energy levels, ionization energies, electron affinities, transition probabilities, hyperfine effects and other properties of atoms and molecules.

The majority of books dealing with prospects for interstellar flight tackle the problem of the propulsion systems that will be needed to send a craft on an interstellar trajectory. The proposed book looks at two other, equally important aspects of such space missions, and each forms half of this two part book.

Part 1 looks at the ways in which it is possible to exploit the focusing effect of the Sun as a gravitational lens for scientific missions to distances of 550 AU and beyond into interstellar space. The author explains the mechanism of the Sun as a gravitational lens, the scientific investigations which may be carried out along the way to a distance of 550 AU (and at the 550 AU sphere itself), the requirements for exiting the Solar System at the highest speed and a range of project ideas for missions entering interstellar space.

Part 2 of the book deals with the problems of communicating between an interstellar spaceship and the Earth, especially at very high speeds. Here the author assesses a range of mathematical tools relating to the Karhunen-Loeve Transform (KLT) for optimal telecommunications, technical topics that may one day enable humans flying around the Galaxy to keep in contact with the Earth. This part of the book opens with a summary of the author's 2003 Pe ek Lecture presented at the IAC in Bremen, which introduces the concept of KLT for engineers and 'newcomers' to the subject. It is planned to include a DVD containing the full mathematical derivations of the KLT for those interested in this important mathematical tool whilst the text itself will contain the various results without outlines of the mathematical proofs. Astronautical engineers will thus be able to see the application of the results without getting bogged down in the mathematics."

This Brief presents a new way of introducing relativity theory, in which perplexing relativistic effects such as time dilation and Lorentz contraction are explained prior to the discussion of Lorentz-transformation. The notion of relativistic mass is shown to contradict the spirit of relativity theory and the true significance of the mass-energy relation is contrasted with the popular view of it. The author discusses the twin paradox from the point of view of both siblings. Last but not least, the fundamentals of general relativity are described, including the recent Gravity Probe B experiment.

All kind ofinformationfrom distant celestialbodies comestous intheform of radiation. Inmost the of electromagnetic cases thisradiation propagation be can as a reasonable in described, terms of This is approximation, rays. truenot inthe but also inthe radio only ofthe electro opticalrange range Forthis the of reason laws areoffundamental magneticspectrum. optics ray for importance and astronomy, astrophysics, cosmology. to According arethe of general relativity, light light likegeodesics a rays Lorentzianmetric whichthe is described. how by spacetimegeometry This, is true as as the under the ever, only long light are rays freelypropagating influence ofthe fieldwhich is coded in the only gravitational spacetime ge If a is in an medium ometry. light ray influenced, addition, by optical (e. g. , then it will not follow ofthe by a a plasma), light like geodesic spacetime metric. It is true that for radiation the electromagnetic traveling through universe the influence ofamedium on the ofthe and usually path on ray the is small. there are several cases inwhich this influ frequency However, ence is well in inthe radio For measurable, particular very range. example, the deflection ofradio inthe field oftheSun is consider gravitational rays influenced the Solarcorona. currentand ably by Moreover, planned Doppler with microwaves in the Solar reach in the an experiments system accuracy 5 of 10 15 whichmakes it totakethe influence frequency Awlw necessary ofthe medium into account.

Each contribution is an article in itself, and great effort has been made by the authors to be lucid and not too technical. A few brief highlights of the round-table discussions are given between the chapters.

Topics include: Quantum non-locality, the measurement problem, quantum insights into relativity, cosmology and thermodynamics, and possible bearings of quantum mechanics to biology and consciousness. Authors include Yakir Aharanov and Anton Zeilinger, plus Nobel laureates Anthony J. Leggett (2003) and Gerardus t Hooft (1999).

Foreword written by Sir Roger Penrose, best-selling author (The Emperor's New Mind) and world-renowned mathematical physicist.

The idea to hold a workshop on globular clusters in Concepcion emerged during 2005 out of a variety of circumstances. Four years had passed since the IAUSymposium 207 onExtragalactic Globular Clusters inPuc' on, atime span, which we thought to be long enough for justifying a new meeting with theintent toreviewthemostrecentdevelopments inthe?eld of extragalactic stars clusters. Originally intended to be a small-scale workshop, the response from the community was overwhelming so that only a full-scale international conferencewas abletocopewith thenumerousrequestsfortalksandposters. Finally, about 160 participants gathered in Concepci' on on March 6th, 2006. The venue was the university lecture hall located in the facultad de - manidadesyartesoftheUniversidaddeConcepci' on.Posterswereexposedin the lobby of the faculty building. The weather was as good as one can reas- ablyexpectfromalatesummerinConcepci' on.Althoughtheprogrammewas so tight that separate poster sessions other than those during co?ee breaks could not be accomodated, posters received a lot of attention. From the ?rst to the last talk, the atmosphere was inspiring and the conference could keep its tension for ?ve full days. This clearly shows that the attraction which globular clusters exercise on astrophysicists of quite di?erent ?avours, is as strong as ever.

Hans Reichenbach, a philosopher of science who was one of five students in Einstein's first seminar on the general theory of relativity, became Einstein's bulldog, defending the theory against criticism from philosophers, physicists, and popular commentators. This book chronicles the development of Reichenbach's reconstruction of Einstein's theory in a way that clearly sets out all of its philosophical commitments and its physical predictions as well as the battles that Reichenbach fought on its behalf, in both the academic and popular press. The essays include reviews and responses to philosophical colleagues, such as Moritz Schlick and Hugo Dingler; polemical discussions with physicists Max Born and D. C. Miller; as well as popular articles meant to clarify aspects of Einstein's theories and set out their philosophical ramifications for the layperson. At a time when physics and philosophy were both undergoing revolutionary changes in content and method, this book is a window into the development of scientific philosophy and the role of the philosopher.

This book offers a presentation of the special theory of relativity that is mathematically rigorous and yet spells out in considerable detail the physical significance of the mathematics. It treats, in addition to the usual menu of topics one is accustomed to finding in introductions to special relativity, a wide variety of results of more contemporary origin. These include Zeeman's characterization of the causal automorphisms of Minkowski spacetime, the Penrose theorem on the apparent shape of a relativistically moving sphere, a detailed introduction to the theory of spinors, a Petrov-type classification of electromagnetic fields in both tensor and spinor form, a topology for Minkowski spacetime whose homeomorphism group is essentially the Lorentz group, and a careful discussion of Dirac's famous Scissors Problem and its relation to the notion of a two-valued representation of the Lorentz group. This second edition includes a new chapter on the de Sitter universe which is intended to serve two purposes. The first is to provide a gentle prologue to the steps one must take to move beyond special relativity and adapt to the presence of gravitational fields that cannot be considered negligible. The second is to understand some of the basic features of a model of the empty universe that differs markedly from Minkowski spacetime, but may be recommended by recent astronomical observations suggesting that the expansion of our own universe is accelerating rather than slowing down. The treatment presumes only a knowledge of linear algebra in the first three chapters, a bit of real analysis in the fourth and, in two appendices, some elementary point-set topology. The first edition of the book received the 1993 CHOICE award for Outstanding Academic Title. Reviews of first edition: ..". a valuable contribution to the pedagogical literature which will be enjoyed by all who delight in precise mathematics and physics." (American Mathematical Society, 1993) "Where many physics texts explain physical phenomena by means of mathematical models, here a rigorous and detailed mathematical development is accompanied by precise physical interpretations." (CHOICE, 1993) ..". his talent in choosing the most significant results and ordering them within the book can't be denied. The reading of the book is, really, a pleasure." (Dutch Mathematical Society, 1993)

The observation, in 1919 by A.S. Eddington and collaborators, of the gra- tational de?ection of light by the Sun proved one of the many predictions of Einstein's Theory of General Relativity: The Sun was the ?rst example of a gravitational lens. In 1936, Albert Einstein published an article in which he suggested - ing stars as gravitational lenses. A year later, Fritz Zwicky pointed out that galaxies would act as lenses much more likely than stars, and also gave a list of possible applications, as a means to determine the dark matter content of galaxies and clusters of galaxies. It was only in 1979 that the ?rst example of an extragalactic gravitational lens was provided by the observation of the distant quasar QSO 0957+0561, by D. Walsh, R.F. Carswell, and R.J. Weymann. A few years later, the ?rst lens showing images in the form of arcs was detected. The theory, observations, and applications of gravitational lensing cons- tute one of the most rapidly growing branches of astrophysics. The gravi- tional de?ection of light generated by mass concentrations along a light path producesmagni?cation,multiplicity,anddistortionofimages,anddelaysp- ton propagation from one line of sight relative to another. The huge amount of scienti?c work produced over the last decade on gravitational lensing has clearly revealed its already substantial and wide impact, and its potential for future astrophysical applications.

This volume contains papers presented at an international conference to celebrate Fred Hoyle's monumental contributions to astronomy, astrophysics and astrobiology and more generally to humanity and culture. The contributed articles highlight the important aspects of his scientific life and show how much of an example and inspiration he has been for over three generations in the 20th century.
There are a few people of whom it could be said they changed the way we perceive the world. Galileo Galilei, Nicholas Copernicus and Isaac Newton were amongst these. The inclusion of Fred Hoyle in this elite group may be contentious at the moment for the reason that in challenging the most cherished of Holy Grails in science he unwittingly offended many. But once the dust has settled over the many disputes that were raised and in the fullness of time there can be little doubt that Fred Hoyle will be ranked alongside these figures of history.
Hoyle perceived science with an indomitable passion and an obsessive desire to find the truth wherever it lay. His singleness of purpose in this great mission and his deep suspicion of orthodoxy, his powerful intellect and imagination set him apart from most of his contemporaries in the last century.
This volume includes papers presented at a commemorative conference held in Cardiff in June 2002. The material divides naturally into several sections: Personal Reminiscences, Stellar Structure and Evolution, Cosmology, Interstellar Matter, Comets and finally Panspermia. Each article pays its own tribute to Fred Hoyle for his inspiration and guidance that led to major breakthroughs in astrophysics and space science throughout the 20th century.

The aim of this book is to give graduate students an overview of quantum gravity but it also covers related topics from astrophysics. Some well-written contributions can serve as an introduction into basic conceptual concepts like time in quantum gravity or the emergence of a classical world from quantum cosmology. This makes the volume attractive to philosophers of science, too. Other topics are black holes, gravitational waves and non-commutative extensions of physical theories.

Observability and Scientific Realism It is commonly thought that the birth of modern natural science was made possible by an intellectual shift from a mainly abstract and specuJative conception of the world to a carefully elaborated image based on observations. There is some grain of truth in this claim, but this grain depends very much on what one takes observation to be. In the philosophy of science of our century, observation has been practically equated with sense perception. This is understandable if we think of the attitude of radical empiricism that inspired Ernst Mach and the philosophers of the Vienna Circle, who powerfully influenced our century's philosophy of science. However, this was not the atti tude of the f ounders of modern science: Galileo, f or example, expressed in a f amous passage of the Assayer the conviction that perceptual features of the world are merely subjective, and are produced in the 'anima!' by the motion and impacts of unobservable particles that are endowed uniquely with mathematically expressible properties, and which are therefore the real features of the world. Moreover, on other occasions, when defending the Copernican theory, he explicitly remarked that in admitting that the Sun is static and the Earth turns on its own axis, 'reason must do violence to the sense' , and that it is thanks to this violence that one can know the tme constitution of the universe.

Digital sky surveys, data from orbiting telescopes, and advances in computation have increased the quantity and quality of astronomical data by several orders of magnitude in recent years. Making sense of this wealth of data requires sophisticated statistical and data analytic techniques. Fortunately, statistical methodologies have similarly made great strides in recent years. Powerful synergies thus emerge when astronomers and statisticians join in examining astrostatistical problems and approaches. The volume focuses on several themes: .The increasing power of Bayesian approaches to modeling astronomical data .The growth of enormous databases, leading an emerging federated Virtual Observatory, and their impact on modern astronomical research .Statistical modeling of critical datasets, such as galaxy clustering and fluctuations in the microwave background radiation, leading to a new era of precision cosmology .Methodologies for uncovering clusters and patterns in multivariate data .The characterization of multiscale patterns in imaging and time series data As in earlier volumes in this series, research contributions discussing topics in one field are joined with commentary from scholars in the other. Short contributed papers covering dozens of astrostatistical topics are also included."

Galaxies have a history. This has become clear from recent sky surveys which have shown that distant galaxies, formed early in the life of the Universe, differ from the nearby ones. New observational windows at ultraviolet, infrared and millimetric wavelengths (provided by ROSAT, IRAM, IUE, IRAS, ISO) have revealed that galaxies contain a wealth of components: very hot gas, atomic hydrogen, molecules, dust, dark matter ...

A significant advance is expected due to new instruments (VLT, FIRST, XMM) which will allow one to explore the most distant Universe. Three Euroconferences have been planned to punctuate this new epoch in galactic research, bringing together specialists in various fields of Astronomy.

The first one, held in Granada (Spain) in May 2000, addressed the observational clues. The second one took place in October 2001 in St Denis de la Reunion (France) and reviewed the basic building blocks and small-scale processes in galaxy evolution. The third one will take place in July 2002 in Kiel (Germany) and will be devoted to the overall modelling of galaxy evolution. This book contains the proceedings of the second conference. It is suitable for researchers and PhD students in Astrophysics. "

Sponsored by the Global Foundation, Inc., these proceedings are derived from the International Conference on Orbis Scientiae II. Topics covered include: gravitational mass, neutrino mass, particle masses, cosmological masses, susy masses, and big bang creation of mass.

General relativity ranks among the most accurately tested fundamental theories in all of physics. Deficiencies in mathematical and conceptual understanding still exist, hampering further progress. This book collects surveys by experts in mathematical relativity writing about the current status of, and problems in, their fields. There are four contributions for each of the following mathematical areas: differential geometry and differential topology, analytical methods and differential equations, and numerical methods.

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.

Here is a systematic approach to such fundamental questions as: What mathematical structures does Einstein-Weyl causality impose on a point-set that has no other previous structure defined on it? The author proposes an axiomatization of the physics inspired notion of Einstein-Weyl causality and investigating the consequences in terms of possible topological spaces. One significant result is that the notion of causality can effectively be extended to discontinuum.

This book looks at answers to the biggest questions in astronomy - the questions of how the planets, stars, galaxies and the universe were formed. Over the last decade, a revolution in observational astronomy has produced possible answers to three of these questions. This book describes this revolution. The one question for which we still do not have an answer is the question of the origin of the universe. In the final chapter, the author looks at the connection between science and philosophy and shows how new scientific results have laid the groundwork for the first serious scientific studies of the origin of the universe.

This is a fascinating and enjoyable popular science book on gravity and black holes. It offers an absorbing account on the history of research on the universe and gravity from Aristotle via Copernicus via Newton to Einstein. The author possesses high literary qualities and is celebrated relativist. The physics of black holes constitutes one of the most fascinating chapters in modern science. At the same time, there is a fanciful quality associated with this strange and beautiful entity. The black hole story is undoubtedly an adventure through physics, philosophy, history, fiction and fantasy. This book is an attempt to blend all these elements together.

In 1997, contrary to the ruling paradigm which was that of a dark matter ?lled, decelerating universe, my work pointed to a dark energydriven- celerating universe with a small cosmological constant. Moreover, the many supposedly accidental Large Number relations in cosmology, including the mysterious Weinbergformula were now deduced from the theory. Obser- tionalcon?rmationforthisscenariocamein1998, whiledarkenergyitselfwas ?nally recon?rmed in 2003, thanks to the Wilkinson Microwave Anisotropy Probe and the Sloan Digital Sky Survey. The 1997, and subsequent work was the consequence of mainly three cons- erations: dark energy or the well known Zero Point Field, fuzzy spacetime and ?uctuations. Indeed String Theory and Quantum Gravity approaches have had to discard the smooth spacetime of General Relativity and Qu- tum Field Theory, in a quest for a uni?ed description of these two pillars of twentieth century physics. This book is the result of some seventy ?ve papers published in international journals, andpartlyanearlierbook,"TheChaoticUniverse: FromthePlanck to the Hubble Scale" (Nova Science, New York, 2001), as also several lectures delivered in Universities and institutes in the United States, Canada and - rope. It describes how, in a simple and somewhat conventional framework, an underpinning of Planck scale oscillators in the ubiquitous Zero Point Field or dark energy leads to a uni?ed description of phenomena involving elementary particles and the cosmos. In particular, apart from the cosmology mentioned above, these considerations lead to a uni?ed description of all interactions, includinggravitation, thoughinanextended gauge ?eld treatment.