05233nam 2200709Ia 450 991078487620332120230607221501.0981-277-837-3(CKB)1000000000402915(EBL)1679686(OCoLC)855898964(SSID)ssj0000136832(PQKBManifestationID)11158687(PQKBTitleCode)TC0000136832(PQKBWorkID)10087661(PQKB)10539422(MiAaPQ)EBC1679686(WSP)00004804(Au-PeEL)EBL1679686(CaPaEBR)ebr10201293(CaONFJC)MIL505455(EXLCZ)99100000000040291520020618d2001 uy 0engur|n|---|||||txtccrDeparametrization and path integral quantization of cosmological models[electronic resource] /Claudio SimeoneSingapore ;River Edge, NJ World Scientificc20011 online resource (152 p.)World scientific lecture notes in physics ;v. 69Description based upon print version of record.981-02-4741-9 Includes bibliographical references and index.Contents ; Preface ; Chapter 1 Introduction ; Chapter 2 The gravitational field as a constrained Hamiltonian system ; 2.1 Momentum and Hamiltonian constraints ; 2.2 Minisuperspaces as constrained systems ; 2.3 Quantization ; 2.3.1 Canonical quantization2.3.2 Path integral quantization Chapter 3 Deparametrization and path integral quantization ; 3.1 The identification of time ; 3.1.1 Gauge fixation and deparametrization ; 3.1.2 Topology of the constraint surface: intrinsic and extrinsic time3.2 Gauge-invariant action for a parametrized system 3.2.1 End point terms ; 3.2.2 Observables and time ; 3.2.3 Non separable constraints ; 3.3 Path integral ; 3.3.1 General formalism ; 3.3.2 The function f and the reduced Hamiltonian. Unitarity ; 3.4 Examples3.4.1 Feynman propagator for the Klein-Gordon equation 3.4.2 The ideal clock ; 3.4.3 Transition probability for empty Friedmann-Robertson-Walker universes ; Chapter 4 Homogeneous relativistic cosmologies ; 4.1 Isotropic universes ; 4.1.1 A toy model ; 4.1.2 True degrees of freedom4.1.3 A more general constraint 4.1.4 Extrinsic time. The closed ""de Sitter"" universe ; 4.1.5 Comment ; 4.2 Anisotropic universes ; 4.2.1 The Kantowski-Sachs universe ; 4.2.2 The Taub universe ; 4.2.3 Other anisotropic models ; Chapter 5 String cosmologies5.1 String theory on background fields The problem of time is a central feature of quantum cosmology: differing from ordinary quantum mechanics, in cosmology there is nothing "outside" the system which plays the role of clock, and this makes difficult the obtention of a consistent quantization. A possible solution is to assume that a subset of the variables describing the state of the universe can be a clock for the remaining of the system. Following this line, in this book a new proposal consisting in the previous identification of time by means of gauge fixation is applied to the quantization of homogeneous cosmological models. World Scientific lecture notes in physics ;v. 69.Quantum gravitySpace and timePath integralsGauge invarianceHamiltonian systemsQuantum gravity.Space and time.Path integrals.Gauge invariance.Hamiltonian systems.523.1Simeone Claudio1473682MiAaPQMiAaPQMiAaPQBOOK9910784876203321Deparametrization and path integral quantization of cosmological models3686938UNINA