Pseudo-Complex General Relativity

Pseudo-Complex General Relativity

Author: Peter O. Hess

Publisher: Springer

Published: 2015-10-31

Total Pages: 263

ISBN-13: 3319250612

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This book explores the role of singularities in general relativity (GR): The theory predicts that when a sufficient large mass collapses, no known force is able to stop it until all mass is concentrated at a point. The question arises, whether an acceptable physical theory should have a singularity, not even a coordinate singularity. The appearance of a singularity shows the limitations of the theory. In GR this limitation is the strong gravitational force acting near and at a super-massive concentration of a central mass. First, a historical overview is given, on former attempts to extend GR (which includes Einstein himself), all with distinct motivations. It will be shown that the only possible algebraic extension is to introduce pseudo-complex (pc) coordinates, otherwise for weak gravitational fields non-physical ghost solutions appear. Thus, the need to use pc-variables. We will see, that the theory contains a minimal length, with important consequences. After that, the pc-GR is formulated and compared to the former attempts. A new variational principle is introduced, which requires in the Einstein equations an additional contribution. Alternatively, the standard variational principle can be applied, but one has to introduce a constraint with the same former results. The additional contribution will be associated to vacuum fluctuation, whose dependence on the radial distance can be approximately obtained, using semi-classical Quantum Mechanics. The main point is that pc-GR predicts that mass not only curves the space but also changes the vacuum structure of the space itself. In the following chapters, the minimal length will be set to zero, due to its smallness. Nevertheless, the pc-GR will keep a remnant of the pc-description, namely that the appearance of a term, which we may call "dark energy", is inevitable. The first application will be discussed in chapter 3, namely solutions of central mass distributions. For a non-rotating massive object it is the pc-Schwarzschild solution, for a rotating massive object the pc-Kerr solution and for a charged massive object it will be the Reissner-Nordström solution. This chapter serves to become familiar on how to resolve problems in pc-GR and on how to interpret the results. One of the main consequences is, that we can eliminate the event horizon and thus there will be no black holes. The huge massive objects in the center of nearly any galaxy and the so-called galactic black holes are within pc-GR still there, but with the absence of an event horizon! Chapter 4 gives another application of the theory, namely the Robertson-Walker solution, which we use to model different outcomes of the evolution of the universe. Finally the capability of this theory to predict new phenomena is illustrated.


New Phenomena And New States Of Matter In The Universe: From Quarks To Cosmos

New Phenomena And New States Of Matter In The Universe: From Quarks To Cosmos

Author: Cesar Augusto Zen Vasconcellos

Publisher: World Scientific

Published: 2023-01-17

Total Pages: 375

ISBN-13: 9811220921

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Recent discoveries in astronomy and relativistic astrophysics as well as experiments on particle and nuclear physics have blurred the traditional boundaries of physics. It is believed that at the birth of the Universe, a whirlwind of matter and antimatter, of quarks and exotic leptons, briefly appeared and merged into a sea of energy. The new phenomena and new states of matter in the Universe revealed the deep connection between quarks and the Cosmos. Motivated by these themes, this book discusses different topics: gravitational waves, dark matter, dark energy, exotic contents of compact stars, high-energy and gamma-ray astrophysics, heavy ion collisions and the formation of the quark-gluon plasma in the early Universe. The book presents some of the latest researches on these fascinating themes and is useful for experts and students in the field.


Walter Greiner Memorial Volume

Walter Greiner Memorial Volume

Author: Peter Otto Hess

Publisher: World Scientific

Published: 2018-04-11

Total Pages: 388

ISBN-13: 9813234296

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Walter Greiner (1935-2016) was a German physicist of the Goethe University, Frankfurt, well-known for his many contributions in scientific research and developments, in particular the field of nuclear physics. He was a well-respected science leader and a teacher who had supervised batches of young collaborators and students, many of whom are now leaders in both academics and industry worldwide. Greiner had a wide interest of science which covered atomic physics, heavy-ion physics, and nuclear astrophysics. Greiner co-founded GSI, the Helmholtz Centre for Heavy Ion Research, and the multi-disciplinary research center, FIAS (Frankfurt Institute for Advanced Studies). Besides numerous professorship with universities worldwide, including the University of Maryland, Greiner received many prestigious prizes in honor of his outstanding contributions, among others are the Otto Hahn Prize and the Max Born Prize.This memorial volume is a special tribute by Greiner's former colleagues, students, and friends honoring his contributions and passion in science. The volume begins with a writing by Greiner about his early days in science. The subsequent articles, comprising personal and scientific reminiscences of Walter Greiner, serve as timely reviews on various topics of current interest.


1st Karl Schwarzschild Meeting on Gravitational Physics

1st Karl Schwarzschild Meeting on Gravitational Physics

Author: Piero Nicolini

Publisher: Springer

Published: 2015-10-28

Total Pages: 392

ISBN-13: 3319200461

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These proceedings collect the selected contributions of participants of the First Karl Schwarzschild Meeting on Gravitational Physics, held in Frankfurt, Germany to celebrate the 140th anniversary of Schwarzschild's birth. They are grouped into 4 main themes: I. The Life and Work of Karl Schwarzschild; II. Black Holes in Classical General Relativity, Numerical Relativity, Astrophysics, Cosmology, and Alternative Theories of Gravity; III. Black Holes in Quantum Gravity and String Theory; IV. Other Topics in Contemporary Gravitation. Inspired by the foundational principle ``By acknowledging the past, we open a route to the future", the week-long meeting, envisioned as a forum for exchange between scientists from all locations and levels of education, drew participants from 15 countries across 4 continents. In addition to plenary talks from leading researchers, a special focus on young talent was provided, a feature underlined by the Springer Prize for the best student and junior presentations.


Relativistic Celestial Mechanics of the Solar System

Relativistic Celestial Mechanics of the Solar System

Author: Sergei Kopeikin

Publisher: John Wiley & Sons

Published: 2011-10-25

Total Pages: 897

ISBN-13: 3527634576

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This authoritative book presents the theoretical development of gravitational physics as it applies to the dynamics of celestial bodies and the analysis of precise astronomical observations. In so doing, it fills the need for a textbook that teaches modern dynamical astronomy with a strong emphasis on the relativistic aspects of the subject produced by the curved geometry of four-dimensional spacetime. The first three chapters review the fundamental principles of celestial mechanics and of special and general relativity. This background material forms the basis for understanding relativistic reference frames, the celestial mechanics of N-body systems, and high-precision astrometry, navigation, and geodesy, which are then treated in the following five chapters. The final chapter provides an overview of the new field of applied relativity, based on recent recommendations from the International Astronomical Union. The book is suitable for teaching advanced undergraduate honors programs and graduate courses, while equally serving as a reference for professional research scientists working in relativity and dynamical astronomy. The authors bring their extensive theoretical and practical experience to the subject. Sergei Kopeikin is a professor at the University of Missouri, while Michael Efroimsky and George Kaplan work at the United States Naval Observatory, one of the world?s premier institutions for expertise in astrometry, celestial mechanics, and timekeeping.


New Horizons in Fundamental Physics

New Horizons in Fundamental Physics

Author: Stefan Schramm

Publisher: Springer

Published: 2016-11-11

Total Pages: 381

ISBN-13: 3319441655

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This volume presents the state-of-the-art in selected topics across modern nuclear physics, covering fields of central importance to research and illustrating their connection to many different areas of physics. It describes recent progress in the study of superheavy and exotic nuclei, which is pushing our knowledge to ever heavier elements and neutron-richer isotopes. Extending nuclear physics to systems that are many times denser than even the core of an atomic nucleus, one enters the realm of the physics of neutron stars and possibly quark stars, a topic that is intensively investigated with many ground-based and outer-space research missions as well as numerous theoretical works. By colliding two nuclei at very high ultra-relativistic energies one can create a fireball of extremely hot matter, reminiscent of the universe very shortly after the big bang, leading to a phase of melted hadrons and free quarks and gluons, the so-called quark-gluon plasma. These studies tie up with effects of crucial importance in other fields. During the collision of heavy ions, electric fields of extreme strength are produced, potentially destabilizing the vacuum of the atomic physics system, subsequently leading to the decay of the vacuum state and the emission of positrons. In neutron stars the ultra-dense matter might support extremely high magnetic fields, far beyond anything that can be produced in the laboratory, significantly affecting the stellar properties. At very high densities general relativity predicts the stellar collapse to a black hole. However, a number of current theoretical activities, modifying Einstein’s theory, point to possible alternative scenarios, where this collapse might be avoided. These and related topics are addressed in this book in a series of highly readable chapters. In addition, the book includes fundamental analyses of the practicalities involved in transiting to an electricity supply mainly based on renewable energies, investigating this scenario less from an engineering and more from a physics point of view. While the topics comprise a large scope of activities, the contributions also show an extensive overlap in the methodology and in the analytical and numerical tools involved in tackling these diverse research fields that are the forefront of modern science.


Topics On Strong Gravity: A Modern View On Theories And Experiments

Topics On Strong Gravity: A Modern View On Theories And Experiments

Author: Cesar Augusto Zen Vasconcellos

Publisher: World Scientific

Published: 2019-12-26

Total Pages: 299

ISBN-13: 9813277351

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'The book concentrates attention on extended alternative theories of gravity and on the best astrophysical laboratories to probe the strong gravity-field regime: black holes, pulsars and neutron stars … Readers will likely share the satisfaction the editor and contributors say they experienced as they organized the book.'SirReadaLotFor more than a century, our understanding of gravitational physics was based on Albert Einstein's theory of General Relativity, which fundamentally changed our understanding of the Universe, its origin, and its evolutionary process. General Relativity accurately describes a large number of phenomena on very different scales. As such, it has been very well tested and its remarkable predictions are compatible with most experimental and observational data. However, the observational and experimental results compatible with General Relativity fall in its vast majority under the weak gravitational field regime. In recent years, discrepancies between the data and the corresponding predictions of General Relativity have been observed and have generated intense research activity. One of the most critical aspects of General Relativity is the presence of singularities in extreme physical situations. These discrepancies indicate that either the parameters of the theory must be modified in the regime of strong field gravity/high energy and large space-time curvature, or the theory itself should be modified. In this book, we focus our attention on extended alternative gravity theories and the best astrophysical laboratories to probe the strong field regime: black holes, pulsars, and neutron stars.


General Relativity

General Relativity

Author: Norbert Straumann

Publisher: Springer Science & Business Media

Published: 2013-11-11

Total Pages: 674

ISBN-13: 3662118270

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The foundations are thoroughly developed together with the required mathematical background from differential geometry developed in Part III. The author also discusses the tests of general relativity in detail, including binary pulsars, with much space is devoted to the study of compact objects, especially to neutron stars and to the basic laws of black-hole physics. This well-structured text and reference enables readers to easily navigate through the various sections as best matches their backgrounds and perspectives, whether mathematical, physical or astronomical. Very applications oriented, the text includes very recent results, such as the supermassive black-hole in our galaxy and first double pulsar system


Fission And Properties Of Neutron-rich Nuclei - Proceedings Of The Fifth International Conference On Icfn5

Fission And Properties Of Neutron-rich Nuclei - Proceedings Of The Fifth International Conference On Icfn5

Author: Joseph H Hamilton

Publisher: World Scientific

Published: 2013-09-16

Total Pages: 746

ISBN-13: 9814525448

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These proceedings are the fifth in the series of International Conferences covering fission and properties of neutron-rich nuclei, which are at the forefront of nuclear research. The time interval of 5 years between each conference allows for significant new results to be achieved. Recently, world leaders in theory and experiments in research and the development of new facilities for research presented their latest results in areas such as synthesis of superheavy elements, new facilities for and recent results with radioactive ion beams, structure of neutron-rich nuclei, nuclear fission process, fission yields and nuclear astrophysics. This book is a major source of the latest research in these areas and plans for the future. The conference brought together a unique group of over 100 speakers including leaders from the major nuclear laboratories in Canada, China, France, Finland, Germany, Italy, Japan, Russia, Switerzland and the US along with leading research scientists from around the world.


Complex General Relativity

Complex General Relativity

Author: Giampiero Esposito

Publisher: Springer Science & Business Media

Published: 2006-04-11

Total Pages: 216

ISBN-13: 0306471183

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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.