 Hardcover edition | |
| Author | Robert Wald |
|---|---|
| Cover artist | René Magritte |
| Country | United States of America |
| Language | English |
| Subject | General relativity |
| Genre | Non-fiction |
| Publisher | The University of Chicago Press |
Publication date | 1984, 2010 |
| Media type | |
| Pages | xiii + 491 |
| ISBN | 0-226-87033-2 |
| OCLC | 10018614 |
| 530.1/1 19 | |
| LC Class | QC173.6 .W35 1984 |
General Relativity is a graduate textbook and reference on Albert Einstein's general theory of relativity written by the gravitational physicist Robert Wald.
First published by the University of Chicago Press in 1984, the book, a tome of almost 500 pages, covers many aspects of the general theory of relativity. It is divided into two parts. Part I covers the fundamentals of the subject and Part II the more advanced topics such as causal structure, and quantum effects. [1] The book uses the abstract index notation for tensors. [2] It treats spinors, the variational-principle formulation, the initial-value formulation, (exact) gravitational waves, singularities, Penrose diagrams, Hawking radiation, and black-hole thermodynamics. [3]
It is aimed at beginning graduate students and researchers. [3] [4] To this end, most of the materials in Part I is geared towards an introductory course on the subject while Part II covers a wide range of advanced topics for a second term or further study. The essential mathematical methods for the formulation of general relativity are presented in Chapters 2 and 3 while more advanced techniques are discussed in Appendices A to C. Wald believes that this is the best way forward because putting all the mathematical techniques at the beginning of the book would prove to be a major obstruction for students while developing these mathematical tools as they get used would mean they are too scattered to be useful. While the Hamiltonian formalism is often presented in conjunction with the initial-value formulation, Wald's coverage of the latter is independent of the former, which is thus relegated to the appendix, alongside the Lagrangian formalism. [4]
This book uses the sign convention for reasons of technical convenience. However, there is one important exception. In Chapter 13 – and only in Chapter 13 –, the sign convention is switched to because it is easier to treat spinors this way. Moreover, this is the most common sign convention used in the literature. [5]
Most of the book uses geometrized units, meaning the fundamental natural constants (Newton's gravitational constant) and (the speed of light in vacuum) are set equal to one, except when predictions that can be tested are made. [5]
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According to Daniel Finley, a professor at the University of New Mexico, this textbook offers good physics intuition. However, the author did not use the most modern mathematical methods available, and his treatment of cosmology is now outdated. Finley believes that the abstract index notation is difficult to learn, though convenient for those who have mastered it. [2]
Theoretical physicist James W. York wrote that General Relativity is a sophisticated yet concise book on the subject that should be appealing to the mathematically inclined, as a high level of rigor is maintained throughout the book. However, he believed the material on linearized gravity is too short, and recommended Gravitation by Charles Misner, Kip Thorne, and John Archibald Wheeler, and Gravitation and Cosmology by Steven Weinberg as supplements. [6]
Hans C. Ohanian, who taught and researched gravitation at the Rensselaer Polytechnic Institute, opined that General Relativity provides a modern introduction to the subject with emphasis on tensor and topological methods and offers some "sharp insights." However, its quality is very variable. Topics such as geodetic motion in the Schwarzschild metric, the Krushkal extension, and energy extraction from black holes, are handled well while empirical tests of Einstein's theory are barely scratched and the treatment of advanced topics, including cosmology, is just too brief to be useful to students. Due to its heavy use of higher mathematics, it may not be suitable for an introductory course. [7]
Lee Smolin argued that General Relativity bridges the gap between the presentation of the material in older textbooks and the literature. For example, while the early pioneers of the subject, including Einstein himself, employed coordinate-based methods, researchers since the mid-1960s have switched to coordinate-free formulations, of which Wald's text is entirely based. Its style is uniformly clear and economic, if too brief at times. Topics that deserve more attention include gravitational radiation and cosmology. However, this book can be supplemented by those by Misner, Thorne, and Wheeler, and by Weinberg. Smolin was teaching a course on general relativity to undergraduates as well as graduate students at Yale University using this book and felt satisfied with the results. He also found it useful as a reference to refresh his memory. [8]
The weak and the strong cosmic censorship hypotheses are two mathematical conjectures about the structure of gravitational singularities arising in general relativity.
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalises special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations.
Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics. It deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vicinity of black holes or similar compact astrophysical objects, such as neutron stars as well as in the early stages of the universe moments after the Big Bang.
A gravitational singularity, spacetime singularity or simply singularity is a condition in which gravity is predicted to be so intense that spacetime itself would break down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by "where" or "when". Gravitational singularities exist at a junction between general relativity and quantum mechanics; therefore, the properties of the singularity cannot be described without an established theory of quantum gravity. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete.
The Large Scale Structure of Space–Time is a 1973 treatise on the theoretical physics of spacetime by the physicist Stephen Hawking and the mathematician George Ellis. It is intended for specialists in general relativity rather than newcomers.
Lee Smolin is an American theoretical physicist, a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo, and a member of the graduate faculty of the philosophy department at the University of Toronto. Smolin's 2006 book The Trouble with Physics criticized string theory as a viable scientific theory. He has made contributions to quantum gravity theory, in particular the approach known as loop quantum gravity. He advocates that the two primary approaches to quantum gravity, loop quantum gravity and string theory, can be reconciled as different aspects of the same underlying theory. He also advocates an alternative view on space and time that he calls temporal naturalism. His research interests also include cosmology, elementary particle theory, the foundations of quantum mechanics, and theoretical biology.
In theoretical physics, the Einstein–Cartan theory, also known as the Einstein–Cartan–Sciama–Kibble theory, is a classical theory of gravitation one of several alternatives to general relativity. The theory was first proposed by Élie Cartan in 1922.
In general relativity and gravitation the Palatini variation is nowadays thought of as a variation of a Lagrangian with respect to the connection.
In theoretical physics, geometrodynamics is an attempt to describe spacetime and associated phenomena completely in terms of geometry. Technically, its goal is to unify the fundamental forces and reformulate general relativity as a configuration space of three-metrics, modulo three-dimensional diffeomorphisms. The origin of this idea can be found in an English mathematician William Kingdon Clifford's works. This theory was enthusiastically promoted by John Wheeler in the 1960s, and work on it continues in the 21st century.
General relativity is a theory of gravitation developed by Albert Einstein between 1907 and 1915. The theory of general relativity says that the observed gravitational effect between masses results from their warping of spacetime.
General relativity is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915, with contributions by many others after 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by those masses.
The Max Planck Institute for Gravitational Physics is a Max Planck Institute whose research is aimed at investigating Einstein's theory of relativity and beyond: Mathematics, quantum gravity, astrophysical relativity, and gravitational-wave astronomy. The institute was founded in 1995 and is located in the Potsdam Science Park in Golm, Potsdam and in Hannover where it closely collaborates with the Leibniz University Hannover. Both the Potsdam and the Hannover parts of the institute are organized in three research departments and host a number of independent research groups.
In relativistic classical field theories of gravitation, particularly general relativity, an energy condition is a generalization of the statement "the energy density of a region of space cannot be negative" in a relativistically phrased mathematical formulation. There are multiple possible alternative ways to express such a condition such that can be applied to the matter content of the theory. The hope is then that any reasonable matter theory will satisfy this condition or at least will preserve the condition if it is satisfied by the starting conditions.
In general relativity, the hole argument is an apparent paradox that much troubled Albert Einstein while developing his famous field equations.
Robert M. Wald is an American theoretical physicist and professor at the University of Chicago. He studies general relativity, black holes, and quantum gravity and has written textbooks on these subjects.
Gravitation is a widely adopted textbook on Albert Einstein's general theory of relativity, written by Charles W. Misner, Kip S. Thorne, and John Archibald Wheeler. It was originally published by W. H. Freeman and Company in 1973 and reprinted by Princeton University Press in 2017. It is frequently abbreviated MTW. The cover illustration, drawn by Kenneth Gwin, is a line drawing of an apple with cuts in the skin to show the geodesics on its surface.
The initial value formulation of general relativity is a reformulation of Albert Einstein's theory of general relativity that describes a universe evolving over time.
Robert Geroch is an American theoretical physicist and professor at the University of Chicago. He has worked prominently on general relativity and mathematical physics and has promoted the use of category theory in mathematics and physics. He was the Ph.D. supervisor for Abhay Ashtekar, Basilis Xanthopoulos and Gary Horowitz. He also proved an important theorem in spin geometry.
In vector calculus, a complex lamellar vector field is a vector field which is orthogonal to a family of surfaces. In the broader context of differential geometry, complex lamellar vector fields are more often called hypersurface-orthogonal vector fields. They can be characterized in a number of different ways, many of which involve the curl. A lamellar vector field is a special case given by vector fields with zero curl.
