Living Reviews in Relativity最新文献

{"title":"The Hole Argument and Some Physical and Philosophical Implications","authors":"John Stachel","doi":"10.12942/lrr-2014-1","DOIUrl":"https://doi.org/10.12942/lrr-2014-1","url":null,"abstract":"<p>This is a historical-critical study of the hole argument, concentrating on the interface between historical, philosophical and physical issues. Although it includes a review of its history, its primary aim is a discussion of the contemporary implications of the hole argument for physical theories based on dynamical, background-independent space-time structures.</p><p>The historical review includes Einstein’s formulations of the hole argument, Kretschmann’s critique, as well as Hilbert’s reformulation and Darmois’ formulation of the general-relativistic Cauchy problem. The 1970s saw a revival of interest in the hole argument, growing out of attempts to answer the question: Why did three years elapse between Einstein’s adoption of the metric tensor to represent the gravitational field and his adoption of the Einstein field equations?</p><p>The main part presents some modern mathematical versions of the hole argument, including both coordinate-dependent and coordinate-independent definitions of covariance and general covariance; and the fiber bundle formulation of both natural and gauge natural theories. By abstraction from continuity and differentiability, these formulations can be extended from differentiable manifolds to any set; and the concepts of permutability and general permutability applied to theories based on relations between the elements of a set, such as elementary particle theories.</p><p>We are closing with an overview of current discussions of philosophical and physical implications of the hole argument.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"17 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2014-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2014-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4246253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays","authors":"Nicolás Yunes,&nbsp;Xavier Siemens","doi":"10.12942/lrr-2013-9","DOIUrl":"https://doi.org/10.12942/lrr-2013-9","url":null,"abstract":"<p>This review is focused on tests of Einstein’s theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein’s theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical <i>strong-field regime</i>. Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4272852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classification of Near-Horizon Geometries of Extremal Black Holes","authors":"Hari K. Kunduri,&nbsp;James Lucietti","doi":"10.12942/lrr-2013-8","DOIUrl":"https://doi.org/10.12942/lrr-2013-8","url":null,"abstract":"<p>Any spacetime containing a degenerate Killing horizon, such as an extremal black hole, possesses a well-defined notion of a near-horizon geometry. We review such near-horizon geometry solutions in a variety of dimensions and theories in a unified manner. We discuss various general results including horizon topology and near-horizon symmetry enhancement. We also discuss the status of the classification of near-horizon geometries in theories ranging from vacuum gravity to Einstein-Maxwell theory and supergravity theories. Finally, we discuss applications to the classification of extremal black holes and various related topics. Several new results are presented and open problems are highlighted throughout.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4992108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing General Relativity with Low-Frequency, Space-Based Gravitational-Wave Detectors","authors":"Jonathan R. Gair,&nbsp;Michele Vallisneri,&nbsp;Shane L. Larson,&nbsp;John G. Baker","doi":"10.12942/lrr-2013-7","DOIUrl":"https://doi.org/10.12942/lrr-2013-7","url":null,"abstract":"<p>We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ～ 10^?5 ? 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4513495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cosmology and Fundamental Physics with the Euclid Satellite","authors":"Luca Amendola,&nbsp;Stephen Appleby,&nbsp;David Bacon,&nbsp;Tessa Baker,&nbsp;Marco Baldi,&nbsp;Nicola Bartolo,&nbsp;Alain Blanchard,&nbsp;Camille Bonvin,&nbsp;Stefano Borgani,&nbsp;Enzo Branchini,&nbsp;Clare Burrage,&nbsp;Stefano Camera,&nbsp;Carmelita Carbone,&nbsp;Luciano Casarini,&nbsp;Mark Cropper,&nbsp;Claudia de Rham,&nbsp;Cinzia Di Porto,&nbsp;Anne Ealet,&nbsp;Pedro G. Ferreira,&nbsp;Fabio Finelli,&nbsp;Juan García-Bellido,&nbsp;Tommaso Giannantonio,&nbsp;Luigi Guzzo,&nbsp;Alan Heavens,&nbsp;Lavinia Heisenberg,&nbsp;Catherine Heymans,&nbsp;Henk Hoekstra,&nbsp;Lukas Hollenstein,&nbsp;Rory Holmes,&nbsp;Ole Horst,&nbsp;Knud Jahnke,&nbsp;Thomas D. Kitching,&nbsp;Tomi Koivisto,&nbsp;Martin Kunz,&nbsp;Giuseppe La Vacca,&nbsp;Marisa March,&nbsp;Elisabetta Majerotto,&nbsp;Katarina Markovic,&nbsp;David Marsh,&nbsp;Federico Marulli,&nbsp;Richard Massey,&nbsp;Yannick Mellier,&nbsp;David F. Mota,&nbsp;Nelson J. Nunes,&nbsp;Will Percival,&nbsp;Valeria Pettorino,&nbsp;Cristiano Porciani,&nbsp;Claudia Quercellini,&nbsp;Justin Read,&nbsp;Massimiliano Rinaldi,&nbsp;Domenico Sapone,&nbsp;Roberto Scaramella,&nbsp;Constantinos Skordis,&nbsp;Fergus Simpson,&nbsp;Andy Taylor,&nbsp;Shaun Thomas,&nbsp;Roberto Trotta,&nbsp;Licia Verde,&nbsp;Filippo Vernizzi,&nbsp;Adrian Vollmer,&nbsp;Yun Wang,&nbsp;Jochen Weller,&nbsp;Tom Zlosnik,&nbsp;The Euclid Theory Working Group","doi":"10.12942/lrr-2013-6","DOIUrl":"https://doi.org/10.12942/lrr-2013-6","url":null,"abstract":"<p>Euclid is a European Space Agency medium-class mission selected for launch in 2019 within the Cosmic Vision 2015–2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky.</p><p>Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis.</p><p>This review has been planned and carried out within Euclid’s Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4446042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum-Spacetime Phenomenology","authors":"Giovanni Amelino-Camelia","doi":"10.12942/lrr-2013-5","DOIUrl":"https://doi.org/10.12942/lrr-2013-5","url":null,"abstract":"<p>I review the current status of phenomenological programs inspired by quantum-spacetime research. I stress in particular the significance of results establishing that certain data analyses provide sensitivity to effects introduced genuinely at the Planck scale. My main focus is on phenomenological programs that affect the directions taken by studies of quantum-spacetime theories.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4497964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relativistic Binaries in Globular Clusters","authors":"Matthew J. Benacquista,&nbsp;Jonathan M. B. Downing","doi":"10.12942/lrr-2013-4","DOIUrl":"https://doi.org/10.12942/lrr-2013-4","url":null,"abstract":"<p>Galactic globular clusters are old, dense star systems typically containing 10⁴–10⁶ stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct <i>N</i>-body integrations and Fokker-Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4171392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Spin-Foam Approach to Quantum Gravity","authors":"Alejandro Perez","doi":"10.12942/lrr-2013-3","DOIUrl":"https://doi.org/10.12942/lrr-2013-3","url":null,"abstract":"This article reviews the present status of the spin-foam approach to the quantization of gravity. Special attention is payed to the pedagogical presentation of the recently-introduced new models for four-dimensional quantum gravity. The models are motivated by a suitable implementation of the path integral quantization of the Plebanski formulation of gravity on a simplicial regularization. The article also includes a self-contained treatment of 2+1 gravity. The simple nature of the latter provides the basis and a perspective for the analysis of both conceptual and technical issues that remain open in four dimensions.","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4565110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Minimal Length Scale Scenarios for Quantum Gravity","authors":"Sabine Hossenfelder","doi":"10.12942/lrr-2013-2","DOIUrl":"https://doi.org/10.12942/lrr-2013-2","url":null,"abstract":"<p>We review the question of whether the fundamental laws of nature limit our ability to probe arbitrarily short distances. First, we examine what insights can be gained from thought experiments for probes of shortest distances, and summarize what can be learned from different approaches to a theory of quantum gravity. Then we discuss some models that have been developed to implement a minimal length scale in quantum mechanics and quantum field theory. These models have entered the literature as the generalized uncertainty principle or the modified dispersion relation, and have allowed the study of the effects of a minimal length scale in quantum mechanics, quantum electrodynamics, thermodynamics, black-hole physics and cosmology. Finally, we touch upon the question of ways to circumvent the manifestation of a minimal length scale in short-distance physics.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5112913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foundations of Black Hole Accretion Disk Theory","authors":"Marek A. Abramowicz,&nbsp;P. Chris Fragile","doi":"10.12942/lrr-2013-1","DOIUrl":"https://doi.org/10.12942/lrr-2013-1","url":null,"abstract":"<p>This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"16 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2013-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2013-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4568195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}