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E-book
Author Enayati, Mohammad

Title The de Sitter (dS) Group and its representations an introduction to elementary systems and modeling the dark energy universe / Mohammad Enayati, Jean-Pierre Gazeau, Hamed Pejhan, Anzhong Wang
Published Cham : Springer, 2023

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Description 1 online resource (223 p.)
Series Synthesis Lectures on Mathematics and Statistics
Synthesis lectures on mathematics and statistics (Springer (Firm))
Contents Intro -- Preface -- Contents -- Acronyms -- Part I De Sitterian Elementary Systems -- 1 Introduction -- [DELETE] -- 1.1 Brief Description -- 1.2 Motivations -- 1.3 Content at a Glance -- 1.4 Reading Guide and Conventions -- Part II As a Preliminary: 1 + 1-Dimensional dS (dS2) Geometry and Relativity -- 2 The Classical Context -- [DELETE] -- 2.1 DS2 Manifold and Its Symmetry Group -- 2.1.1 Precision on SO0(1,2): A Geometric Viewpoint -- 2.1.2 Homomorphism Between SO0(1,2) and SU(1,1) -- 2.2 Relativistic Meaning of the dS2 Group: Group Decomposition -- 2.2.1 Space-Time-Lorentz Decomposition
2.2.2 Cartan Decomposition -- 2.2.3 Iwasawa Decomposition -- 2.3 DS2 Lie Algebra and Classical Phase Spaces -- 2.3.1 Co-adjoint Orbits: A Brief Introduction -- 2.3.2 DS2 (co-)Adjoint Orbits as Possible Phase Spaces for Motions on dS2 Spacetime -- 3 The Quantum-Mechanical Context -- [DELETE] -- 3.1 UIR's of the dS2 Group and Quantum Version of dS2 Motions -- 3.2 UIR's of the dS2 Group: Global Realization -- 3.2.1 Group Representations: A Brief Introduction -- 3.2.2 Principal Series -- 3.2.3 Complementary Series -- 3.2.4 Discrete Series -- Part III 1 + 3-Dimensional dS (dS4) Geometry and Relativity
4 The Classical Context -- [DELETE] -- 4.1 DS4 Manifold and Its Causal Structure -- 4.2 DS4 Relativity Group SO0(1,4) and Its Covering Sp(2,2) -- 4.2.1 Homomorphism Between SO0(1,4) and Sp(2,2) and Some Discrete Symmetries -- 4.3 Relativistic Meaning of the dS4 Group: Group Decomposition -- 4.3.1 Space-Time-Lorentz Decomposition -- 4.3.2 Cartan Decomposition -- 4.3.3 Iwasawa Decomposition -- 4.3.4 Four Integration Formulas on Sp(2,2) -- 4.4 Relativistic Meaning of the dS4 Group: Group (Algebra) Contraction -- 4.4.1 Group (Algebra) Contraction: A Brief Introduction
4.4.2 DS4 Group (Algebra) Contractions -- 4.5 DS4 Lie Algebra and Classical Phase Spaces -- 4.5.1 Phase Space for Scalar ̀̀Massive''/̀̀Massless'' Elementary Systems in dS4 Spacetime -- 4.5.2 Phase Space for ̀̀Spin''̀̀Massive'' Elementary Systems in dS4 Spacetime -- 4.5.3 Phase Space for ̀̀Spin'' (or Helicity) ̀̀Massless'' Elementary Systems in dS4 Spacetime -- 5 The Quantum-Mechanical Context -- [DELETE] -- 5.1 UIR's of the dS4 Group and Quantum Version of dS4 Motions -- 5.1.1 Discrete Series -- 5.1.2 Principal Series -- 5.1.3 Complementary Series
5.1.4 Discussion: A Natural Fuzzyness of dS4 Spacetime -- 5.2 UIR's of the dS4 Group: Global Realization -- 5.2.1 Principal Series: Scalar Case -- 5.2.2 Principal Series: General Case -- 5.2.3 Principal Series: Restriction to the Maximal Compact Subgroup SU(2) timesSU(2) -- 5.2.4 Complementary Series -- 5.2.5 Discrete Series -- 5.3 ̀̀Massive''/̀̀Massless'' dS4 UIR's and the Poincaré Contraction -- 5.3.1 Group Contraction (The Representation Level): A Brief Introduction -- 5.3.2 DS4 Massive UIR's -- 5.3.3 DS4 Massless UIR's
Summary This book reviews the construction of elementary systems living in de Sitter (dS) spacetime, in both the classical and quantum senses. Field theories on dS spacetime are among the most studied mathematical models of the Universe, whether for its earlier period (inflationary phase) or for its current phase of expansion acceleration (dark energy or cosmological constant). Classical elementary systems are Hamiltonian phase spaces, which are associated with co-adjoint orbits of the relativity group. On the other hand, quantum elementary systems are associated with (projective) unitary irreducible representations of the (possibly extended) relativity group (or one of its covering). This study emphasizes the conceptual issues arising in the formulation of such systems and discusses known results in a mathematically rigorous way. Particular attention is paid to: smooth transition from classical to quantum theory; physical content under vanishing curvature, from the point of view of a local (tangent)Minkowskian observer; and thermal interpretation (on the quantum level), in the sense of the Gibbons-Hawking temperature. Such a mathematical construction is of paramount importance to the understanding of the early Universe (due to the critical role that the dS metric plays in the inflationary cosmological scenarii) as well as to the construction of possible models for late-time cosmology (since a small positive cosmological constant or dark energy seems to be required by recent data). In this sense, this book uniquely blends mathematical physics (spacetime symmetry on classical and quantum levels) and theoretical physics (quantization, quantum field theory, and cosmology). Moreover, the level of exposition varies in different parts of the book so that both experts and beginners alike can utilize the book. In addition, this book: Presents consistent formulations of dS elementary systems on three levels; classical mechanics, quantum mechanics, and the quantum field theory Blends mathematical physics (spacetime symmetry on classical and quantum levels) and theoretical physics (quantization, quantum field theory, and cosmology) to uniquely introduce the mathematical structure of dS relativity Discusses conceptual considerations/worries that arise in the formulation of elementary systems
Notes 5.3.4 Discussion: Rehabilitating the dS4 Physics from the Point of View of a Local Minkowskian Observer
Bibliography Includes bibliographical references and index
Notes Online resource; title from PDF title page (SpringerLink, viewed December 15, 2022)
Subject Space and time.
Field theory (Physics)
Field theory (Physics)
Space and time
Form Electronic book
Author Gazeau, Jean-Pierre.
Pejhan, Hamed
Wang, Anzhong
ISBN 9783031160455
3031160452