Background Independence In Classical And Quantum Gravity

Download or read book Background Independence in Classical and Quantum Gravity written by James Read and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is often claimed that any quantum theory of gravity needs its defining equations to be independent of a particular spacetime geometry. James Read illuminates our understanding of background independence by mapping its possible definitions and assessing how various classical and quantum theories of gravity fare on these criteria.

Download or read book Background Independence in Classical and Quantum Gravity written by James Read and published by Oxford University Press. This book was released on 2024-02-09 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is often claimed that Einstein's magnum opus---his 1915 theory of General Relativity---is distinguished from other theories of space and time in virtue of its background independence. It's also often claimed that background independence is an essential feature of any quantum theory of gravity. But are these claims true? This book aspires to offer definitive answers to both of these questions, by (a) charting the space of possible definitions of background independence, and (b) applying said definitions to various classical and quantum theories of gravity. The outcome, in brief, is as follows: General Relativity is not unique by virtue of its background independence (and, indeed, fails to be background independent on some popular definitions); moreover, the situation in the case of quantum theories of gravity is delicate, because (i) there are viable such theories which (by some accounts, at least) fail to be background independent, but also (ii) theories (e.g. perturbative string theory) which have often been dismissed for (allegedly) being background dependent in fact, on many accounts, are better classified as background independent. In giving these answers in rigorous detail, this book seeks to elevate the standards and generality of future discussions of background independence in the foundations of spacetime theories.

Download or read book Beyond Spacetime written by Nick Huggett and published by Cambridge University Press. This book was released on 2020-05-14 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of essays discussing the philosophy and foundations of quantum gravity. Written by leading philosophers and physicists in the field, chapters cover the important conceptual questions in the search for a quantum theory of gravity, and the current state of understanding among philosophers and physicists.

Download or read book The Problem of Time written by Edward Anderson and published by Springer. This book was released on 2017-09-18 with total page 917 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon entertaining background independence in classical (rather than quantum) physics. By this development, and interpreting shape theory as modelling background independence, this book further establishes background independence as a field of study. Background independent mechanics, as well as minisuperspace (spatially homogeneous) models of GR and perturbations thereabout are used to illustrate these points. As hitherto formulated, the different facets of the Problem of Time greatly interfere with each others' attempted resolutions. This book explains how, none the less, a local resolution of the Problem of Time can be arrived at after various reconceptualizations of the facets and reformulations of their mathematical implementation. Self-contained appendices on mathematical methods for basic and foundational quantum gravity are included. Finally, this book outlines how supergravity is refreshingly different from GR as a realization of background independence, and what background independence entails at the topological level and beyond.

Download or read book Three Roads To Quantum Gravity written by Lee Smolin and published by Basic Books. This book was released on 2008-03-18 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: "It would be hard to imagine a better guide to this difficult subject." -- Scientific American In Three Roads to Quantum Gravity, Lee Smolin provides an accessible overview of the attempts to build a final "theory of everything." He explains in simple terms what scientists are talking about when they say the world is made from exotic entities such as loops, strings, and black holes and tells the fascinating stories behind these discoveries: the rivalries, epiphanies, and intrigues he witnessed firsthand. "Provocative, original, and unsettling." -- The New York Review of Books "An excellent writer, a creative thinker." -- Nature

Download or read book The Emergence of Spacetime in String Theory written by Tiziana Vistarini and published by Routledge. This book was released on 2019-06-12 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of space and time is one of the most fascinating and fundamental philosophical issues which presently engages at the deepest level with physics. During the last thirty years this notion has been object of an intense critical review in the light of new scientific theories which try to combine the principles of both general relativity and quantum theory—called theories of quantum gravity. This book considers the way string theory shapes its own account of spacetime disappearance from the fundamental level.

Download or read book Quantum Gravity written by Carlo Rovelli and published by Cambridge University Press. This book was released on 2007-11-29 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum gravity is perhaps the most important open problem in fundamental physics. It is the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. The loop and spinfoam approach, presented in this 2004 book, is one of the leading research programs in the field. The first part of the book discusses the reformulation of the basis of classical and quantum Hamiltonian physics required by general relativity. The second part covers the basic technical research directions. Appendices include a detailed history of the subject of quantum gravity, hard-to-find mathematical material, and a discussion of some philosophical issues raised by the subject. This fascinating text is ideal for graduate students entering the field, as well as researchers already working in quantum gravity. It will also appeal to philosophers and other scholars interested in the nature of space and time.