Download or read book Extensions of f R Gravity written by Tiberiu Harko and published by Cambridge University Press. This book was released on 2018-11-29 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a detailed analysis of modified theories of gravity, discussing their development, cosmological and astrophysical implications and outstanding challenges.
Download or read book Extensions of f R Gravity written by Tiberiu Harko and published by Cambridge University Press. This book was released on 2018-11-08 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent cosmological observations have posed a challenge for traditional theories of gravity: what is the force driving the accelerated expansion of the universe? What if dark energy or dark matter do not exist and what we observe is a modification of the gravitational interaction that dominates the universe at large scales? Various extensions to Einstein's General Theory of Relativity have been proposed, and this book presents a detailed theoretical and phenomenological analysis of several leading, modified theories of gravity. Theories with generalised curvature-matter couplings are first explored, followed by hybrid metric-Palatini gravity. This timely book first discusses key motivations behind the development of these modified gravitational theories, before presenting a detailed overview of their subsequent development, mathematical structure, and cosmological and astrophysical implications. Covering recent developments and with an emphasis on astrophysical and cosmological applications, this is the perfect text for graduate students and researchers.
Download or read book Noether Symmetries in Theories of Gravity written by Francesco Bajardi and published by Cambridge University Press. This book was released on 2022-11-24 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume summarizes the many alternatives and extensions to Einstein's General Theory of Relativity, and shows how symmetry principles can be applied to identify physically viable models. The first part of the book establishes the foundations of classical field theory, providing an introduction to symmetry groups and the Noether theorems. A quick overview of general relativity is provided, including discussion of its successes and shortcomings, then several theories of gravity are presented and their main features are summarized. In the second part, the 'Noether Symmetry Approach' is applied to theories of gravity to identify those which contain symmetries. In the third part of the book these selected models are tested through comparison with the latest experiments and observations. This constrains the free parameters in the selected models to fit the current data, demonstrating a useful approach that will allow researchers to construct and constrain modified gravity models for further applications.
Download or read book Introduction to Modified Gravity written by Albert Petrov and published by Springer Nature. This book was released on 2020-07-27 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews various modified gravity models, including those with modifications in the pure gravitational sector; those involving extra fields, that is, scalar-tensor and vector-tensor gravity theories; gravity models with Lorentz symmetry breaking; and nonlocal gravity models. The authors discuss both classical and quantum aspects of these theories. The book is unique in bringing together all the current alternatives to Einstein gravity in one source and serves as an excellent starting point for graduate students and other newcomers seeking an overview.
Download or read book Beyond Einstein Gravity written by Salvatore Capozziello and published by Springer Science & Business Media. This book was released on 2010-10-27 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beyond Einstein’s Gravity is a graduate level introduction to extended theories of gravity and cosmology, including variational principles, the weak-field limit, gravitational waves, mathematical tools, exact solutions, as well as cosmological and astrophysical applications. The book provides a critical overview of the research in this area and unifies the existing literature using a consistent notation. Although the results apply in principle to all alternative gravities, a special emphasis is on scalar-tensor and f(R) theories. They were studied by theoretical physicists from early on, and in the 1980s they appeared in attempts to renormalize General Relativity and in models of the early universe. Recently, these theories have seen a new lease of life, in both their metric and metric-affine versions, as models of the present acceleration of the universe without introducing the mysterious and exotic dark energy. The dark matter problem can also be addressed in extended gravity. These applications are contributing to a deeper understanding of the gravitational interaction from both the theoretical and the experimental point of view. An extensive bibliography guides the reader into more detailed literature on particular topics.
Download or read book Modified Gravity and Cosmology written by Emmanuel N. Saridakis and published by Springer Nature. This book was released on 2021-12-10 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a focus on modified gravity this book presents a review of the recent developments in the fields of gravity and cosmology, presenting the state of the art, high-lighting the open problems, and outlining the directions of future research. General Relativity and the ΛCDM framework are currently the standard lore and constitute the concordance paradigm of cosmology. Nevertheless, long-standing open theoretical issues, as well as possible new observational ones arising from the explosive development of cosmology in the last two decades, offer the motivation and lead a large amount of research to be devoted in constructing various extensions and modifications. In this review all extended theories and scenarios are first examined under the light of theoretical consistency, and are then applied in various geometrical backgrounds, such as the cosmological and the spherical symmetric ones. Their predictions at both the background and perturbation levels, and concerning cosmology at early, intermediate and late times, are then confronted with the huge amount of observational data that astrophysics and cosmology has been able to offer in the last two decades. Theories, scenarios and models that successfully and efficiently pass the above steps are classified as viable and are candidates for the description of Nature, allowing readers to get a clear overview of the state of the art and where the field of modified gravity is likely to go. This work was performed in the framework of the COST European Action “Cosmology and Astrophysics Network for Theoretical Advances and Training Actions” - CANTATA.
Download or read book The Large Scale Structure of Space Time written by Stephen W. Hawking and published by Cambridge University Press. This book was released on 2023-02-16 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1973, this influential work discusses Einstein's General Theory of Relativity to show how two of its predictions arise: first, that the ultimate fate of many massive stars is to undergo gravitational collapse to form 'black holes'; and second, that there was a singularity in the past at the beginning of the universe. Starting with a precise formulation of the theory, including the necessary differential geometry, the authors discuss the significance of space-time curvature and examine the properties of a number of exact solutions of Einstein's field equations. They develop the theory of the causal structure of a general space-time, and use it to prove a number of theorems establishing the inevitability of singularities under certain conditions. A Foreword contributed by Abhay Ashtekar and a new Preface from George Ellis help put the volume into context of the developments in the field over the past fifty years.
Download or read book Chern Simons super Gravity written by Mokhtar Hassaine and published by World Scientific. This book was released on 2016 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book grew out of a set of lecture notes on gravitational Chern–Simons (CS) theories developed over the past decade for several schools and different audiences including graduate students and researchers. CS theories are gauge-invariant theories that can include gravity consistently. They are only defined in odd dimensions and represent a very special class of theories in the Lovelock family. Lovelock gravitation theories are the natural extensions of General Relativity for dimensions greater than four that yield second-order field equations for the metric. These theories also admit local supersymmetric extensions where supersymmetry is an off-shell symmetry of the action, as in a standard gauge theory. Apart from the arguments of mathematical elegance and beauty, the gravitational CS actions are exceptionally endowed with physical attributes that suggest the viability of a quantum interpretation. CS theories are gauge-invariant, scale-invariant and background independent; they have no dimensional coupling constants. All constants in the Lagrangian are fixed rational coefficients that cannot be adjusted without destroying gauge invariance. This exceptional status of CS systems makes them classically interesting to study, and quantum mechanically intriguing and promising."--Provided by publisher.
Download or read book Relativistic Cosmology written by George F. R. Ellis and published by Cambridge University Press. This book was released on 2012-03-22 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surveying key developments and open issues in cosmology for graduate students and researchers, this book focuses on the general concepts and relations that underpin the standard model of the Universe. It also examines anisotropic and inhomogeneous models, and deeper issues, such as quantum cosmology and the multiverse proposal.
Download or read book Invariance Principles and Extended Gravity written by Salvatore Capozziello and published by Nova Science Pub Incorporated. This book was released on 2010-07-01 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents information on the study of gravitational theories which can be seen as modifications or extensions of General Relativity. The basic principles that a gravitational theory should follow, and their geometrical interpretation, are analysed in a broad perspective which highlights the basic assumptions of General Relativity and suggests possible modifications. In particular, the invariance principles that are related to the gravitational field are presented, showing how gravity can emerge as a gauge theory. Also, the boundle approach to gravity and derive geometrical quantities which intervene in the construction of gravitational field are discussed.
Download or read book Gravity Particles and Space Time written by P I Pronin and published by World Scientific. This book was released on 1996-04-12 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises original and review articles on the frontier problems of the gravitation theory, theoretical and mathematical physics. The volume is dedicated to the memory of Professor Dmitri Ivanenko who made the great contribution to the physical science of the twentieth century. Contents:A Gauge-Invariant Theory of Motion of Charged Test Particles (D Chruscinski & J Kijowski)Heisenberg Picture for Quantized Fields Interacting with Nonstationary Electromagnetic or Gravitational Background (A A Lobashov & V M Mostepanenko)General Relativity as a Gauge Theory of Orthogonal Groups in Three Dimensions (M Raiteri et al.)Quantum Spacetime (D Finkelstein et al.)Jacobi's Principle and Hertz' Definition of Time (H-J Treder et al.)Placing Limits on Cartan's Torsion from Non-Riemannian Crystals (L C G de Andrade)Spinors as Differential Forms, and Applications to Electromagnetism and Quantum Mechanics (W A Rodrigues, Jr & J Vaz, Jr)Black Holes, Time Arrow, and Vacuum in Quantum Electrodynamics (M E Gertsenstein)One-Loop Background Calculations in the General Field Theory (P I Pronin & K V Stepanyantz)Energy–Momentum Superpotential in Gravitation Theory (G Giachetta & G Sardanashvily)and other papers Readership: Physicists, astronomists, high energy physicists, cosmologists and astrophysicists. keywords:Gravitation Theory;Riemannian Geometry;Gauge Theory;Spinor Field;Dirac Operator;Clifford Algebra;Torsion;Quantum Field;Black Hole;Conservation Law“… the book properly reflects the state of the art in a sector of current research on gravitation (and, less so, other fundamental interactions) and spacing geometry.”H Goenner Classical and Quantum Gravity
Download or read book Semiclassical and Stochastic Gravity written by Bei-Lok B. Hu and published by Cambridge University Press. This book was released on 2020-03-05 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of semi-classical gravity theory and stochastic gravity as theories of quantum gravity in curved space-time.
Download or read book Lorentzian Wormholes written by Matt Visser and published by American Institute of Physics. This book was released on 1995 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drawing on pivotal work by Einstein, Wheeler, Thorne, Hawking, and others, Matt Visser charts the development and current state of Lorentzian wormhole physics. Dr. Visser shows that by pushing established physical theories to their limits, it is possible to deduce the true physics of such exotica as wormholes and time travel. The physical framework he uses is derived from one of the major research frontiers of modern theoretical physics: quantum gravity the intersection of classical Einstein gravity and quantum field theory. About the Author Matt Visser is Research Assistant Professor at Washington University, St. Louis. He has lectured in the United States and abroad on topics including wormhole physics, time travel, and the chronology protection conjecture. He has conducted postdoctoral research at both the University of Southern California and at Los Alamos National Laboratory.
Download or read book Gravity from the Ground Up written by Bernard Schutz and published by Cambridge University Press. This book was released on 2003-12-04 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book invites the reader to understand our Universe, not just marvel at it. From the clock-like motions of the planets to the catastrophic collapse of a star into a black hole, gravity controls the Universe. Gravity is central to modern physics, helping to answer the deepest questions about the nature of time, the origin of the Universe and the unification of the forces of nature. Linking key experiments and observations through careful physical reasoning, the author builds the reader's insight step-by-step from simple but profound facts about gravity on Earth to the frontiers of research. Topics covered include the nature of stars and galaxies, the mysteries of dark matter and dark energy, black holes, gravitational waves, inflation and the Big Bang. Suitable for general readers and for undergraduate courses, the treatment uses only high-school level mathematics, supplemented by optional computer programs, to explain the laws of physics governing gravity.
Download or read book Covariant Loop Quantum Gravity written by Carlo Rovelli and published by Cambridge University Press. This book was released on 2015 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensible introduction to the most fascinating research in theoretical physics: advanced quantum gravity. Ideal for researchers and graduate students.
Download or read book Gravity Currents And Intrusions Analysis And Prediction written by Marius Ungarish and published by World Scientific. This book was released on 2020-12-08 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow of gravity currents and intrusions is a subject of active research and engineering application. Currently, there are no formal teaching courses for this topic. Materials and information available in the market are scattered and dated. Researchers and engineers face difficulties in acquiring the 'state-of-the-art' knowledge. The book bridges this gap between the need and supply of the relevant insight and know-how.Written by a renowned author who is a recognized authority in the field, this unique compendium assembles the relevant knowledge into a systematic and unified framework. The presentation is gradual from the elementary to the frontier, and accessible to readers with only a basic background in fluid mechanics and applied mathematics. This will facilitate the systematic acquirement and application of available knowledge to both practical problems and further research.This must-have volume is a useful monograph — that can also serve as a textbook in advanced courses — for researchers, students, engineers and applied mathematicians in the fields of civil engineering, hydraulic engineering, mechanical engineering, ocean engineering and environmental engineering.
Download or read book Modified Gravity written by Baojiu Li and published by World Scientific Publishing Company. This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravity beyond general relativity / Kazuya Koyama -- Parametrizations for tests of gravity / Lucas Lombriser -- Simulation techniques / Claudio Llinares -- Approximation methods in modified gravity models / Baojiu Li -- Large-scale structure probes of modified gravity / Catherine Heymans and Gong-Bo Zhao -- Tests of gravity with galaxy clusters / Matteo Cataneo -- Towards testing gravity with cosmic voids / Yan-Chuan Cai -- Astrophysical tests of screened modified gravity / Jeremy Sakstein -- Laboratory constraints / Philippe Brax.
