Broken Symmetry In Curved Spacetime And Gravity

This book contains several recent articles written about broken spacetime symmetry. The context is curved spacetime as used in General Relativity and the broken symmetry most discussed is Local Lorentz Symmetry. While there is currently no experimental evidence for broken Lorentz symmetry in nature, it is an object of great study from theoretical, phenomenological, and experimental perspectives. All three appear in this volume. There are three review articles in this volume: Fabian Kislat summarizes astrophysical probes of Lorentz violation, especially those using polarized light; Michael Seifert discusses a particular limit of the Standard-Model Extension that is useful for relating theoretical and experimental ideas; and Marco Schreck describes circumstances under which gravitational Cerenkov radiation could arise from Lorentz violation. The other three articles focus more on original research: Charles Lane and Quentin Bailey relate a particular theory of noncommutative geometry to the curved-spacetime Standard-Model Extension; Yuri Bonder and Christobal Corral consider the existence of spacetime symmetries in models with explicit Lorentz violation; and Pawel Gusin et al. study a spacetime transformation that relates the inside and outside of a nonrotating black hole.

This book contains several recent articles written about broken spacetime symmetry. The context is curved spacetime as used in General Relativity and the broken symmetry most discussed is Local Lorentz Symmetry. While there is currently no experimental evidence for broken Lorentz symmetry in nature, it is an object of great study from theoretical, phenomenological, and experimental perspectives. All three appear in this volume. There are three review articles in this volume: Fabian Kislat summarizes astrophysical probes of Lorentz violation, especially those using polarized light; Michael Seifert discusses a particular limit of the Standard-Model Extension that is useful for relating theoretical and experimental ideas; and Marco Schreck describes circumstances under which gravitational Cerenkov radiation could arise from Lorentz violation. The other three articles focus more on original research: Charles Lane and Quentin Bailey relate a particular theory of noncommutative geometry to the curved-spacetime Standard-Model Extension; Yuri Bonder and Christobal Corral consider the existence of spacetime symmetries in models with explicit Lorentz violation; and Pawel Gusin et al. study a spacetime transformation that relates the inside and outside of a nonrotating black hole.

YangOCoMills gravity is a new theory, consistent with experiments, that brings gravity back to the arena of gauge field theory and quantum mechanics in flat space-time. It provides solutions to long-standing difficulties in physics, such as the incompatibility between Einstein''s principle of general coordinate invariance and modern schemes for a quantum mechanical description of nature, and Noether''s OCyTheorem IIOCO which showed that the principle of general coordinate invariance in general relativity leads to the failure of the law of conservation of energy. YangOCoMills gravity in flat space-time appears to be more physically coherent than conventional gravity in curved space-time. The problems of quantization of the gravitational field, the operational meaning of space-time coordinates and momenta, and the conservation of energy-momentum are all resolved in YangOCoMills gravity.The aim of this book is to provide a treatment of quantum YangOCoMills gravity, with an emphasis on the ideas and evidence that the gravitational field is the manifestation of space-time translational symmetry in flat space-time, and that there exists a fundamental space-time symmetry framework that can encompass all of physics, including gravity, for all inertial and non-inertial frames of reference.

An overview of semi-classical gravity theory and stochastic gravity as theories of quantum gravity in curved space-time.

This book presents a review of various issues related to Lorentz symmetry breaking. Explicitly, we consider (i) motivations for introducing Lorentz symmetry breaking, (ii) classical aspects of Lorentz-breaking field theory models including typical forms of Lorentz-breaking additive terms, wave propagation in Lorentz-breaking theories, and mechanisms for breaking the Lorentz symmetry; (iii) quantum corrections in Lorentz-breaking theories, especially the possibilities for perturbation generating the most interesting Lorentz-breaking terms; (iv) correspondence between non-commutative field theories and Lorentz symmetry breaking; (v) supersymmetric Lorentz-breaking theories; and (vi) Lorentz symmetry breaking in a curved space-time. We close the book with the review of experimental studies of Lorentz symmetry breaking. The importance and relevance of these topics are explained, first, by studies of limits of applicability of the Lorentz symmetry, second, by searches of the possible extensions of the standard model, including the Lorentz-breaking ones, and need to study their properties, third, by the relation between Lorentz symmetry breaking with string theory, fourth, by the problem of formulating a consistent quantum gravity theory, so that various modified gravity models are to be examined.

Quantum field theory in curved spacetime has been remarkably fruitful. It can be used to explain how the large-scale structure of the universe and the anisotropies of the cosmic background radiation that we observe today first arose. Similarly, it provides a deep connection between general relativity, thermodynamics, and quantum field theory. This book develops quantum field theory in curved spacetime in a pedagogical style, suitable for graduate students. The authors present detailed, physically motivated, derivations of cosmological and black hole processes in which curved spacetime plays a key role. They explain how such processes in the rapidly expanding early universe leave observable consequences today, and how in the context of evaporating black holes, these processes uncover deep connections between gravitation and elementary particles. The authors also lucidly describe many other aspects of free and interacting quantized fields in curved spacetime.

This textbook presents a detailed introduction to the general concepts of quantum field theory, with special emphasis on principal aspects of functional methods and renormalization in gauge theories, and includes an introduction to semiclassical and perturbative quantum gravity in flat and curved spacetimes.

In part one of Effective Action in Quantum Gravity, the book describes the principles of quantum field theory and the significance of and theory behind effective action. Part two deals with quantum field theory in curved space-time and the effective action. These two parts provide the tools for understanding the rest of the book, which is devoted to selected problems of quantum gravity where the effective action plays a major role. The book assumes only a basic understanding of quantum field theory and general relativity and will be of interest to postgraduate students and researchers in theoretical high-energy physics and gravitational theory.