Living Reviews in Relativity最新文献_第10页

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2010-09-14 DOI: 10.12942/lrr-2010-5

Roy Maartens, Kazuya Koyama

{"title":"Brane-World Gravity","authors":"Roy Maartens, Kazuya Koyama","doi":"10.12942/lrr-2010-5","DOIUrl":"https://doi.org/10.12942/lrr-2010-5","url":null,"abstract":"The observable universe could be a 1+3-surface (the “brane”) embedded in a 1+3+d-dimensional spacetime (the “bulk”), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (～ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity “leaks” into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies — the 5-dimensional Dvali-Gabadadze-Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":null,"pages":null},"PeriodicalIF":40.6,"publicationDate":"2010-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2010-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4587823","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}

引用次数: 965

The Pioneer Anomaly 先锋号异常

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2010-09-01 DOI: 10.12942/lrr-2010-4

Slava G. Turyshev, Viktor T. Toth

{"title":"The Pioneer Anomaly","authors":"Slava G. Turyshev, Viktor T. Toth","doi":"10.12942/lrr-2010-4","DOIUrl":"https://doi.org/10.12942/lrr-2010-4","url":null,"abstract":"Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20–70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ～ 6 × 10?9 Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of aP = (8.74 ± 1.33) × 10?10 m/s2. This apparent violation of the Newton’s gravitational inverse-square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":null,"pages":null},"PeriodicalIF":40.6,"publicationDate":"2010-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2010-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4412422","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}

引用次数: 148

f(R) Theories f (R)的理论

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2010-06-23 DOI: 10.12942/lrr-2010-3

Antonio De Felice, Shinji Tsujikawa

引用次数: 2791

Cosmic Censorship for Gowdy Spacetimes 高迪太空时报的宇宙审查制度

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2010-04-13 DOI: 10.12942/lrr-2010-2

Hans Ringström

{"title":"Cosmic Censorship for Gowdy Spacetimes","authors":"Hans Ringström","doi":"10.12942/lrr-2010-2","DOIUrl":"https://doi.org/10.12942/lrr-2010-2","url":null,"abstract":"Due to the complexity of Einstein’s equations, it is often natural to study a question of interest in the framework of a restricted class of solutions. One way to impose a restriction is to consider solutions satisfying a given symmetry condition. There are many possible choices, but the present article is concerned with one particular choice, which we shall refer to as Gowdy symmetry. We begin by explaining the origin and meaning of this symmetry type, which has been used as a simplifying assumption in various contexts, some of which we shall mention. Nevertheless, the subject of interest here is strong cosmic censorship. Consequently, after having described what the Gowdy class of spacetimes is, we describe, as seen from the perspective of a mathematician, what is meant by strong cosmic censorship. The existing results on cosmic censorship are based on a detailed analysis of the asymptotic behavior of solutions. This analysis is in part motivated by conjectures, such as the BKL conjecture, which we shall therefore briefly describe. However, the emphasis of the article is on the mathematical analysis of the asymptotics, due to its central importance in the proof and in the hope that it might be of relevance more generally. The article ends with a description of the results that have been obtained concerning strong cosmic censorship in the class of Gowdy spacetimes.","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":null,"pages":null},"PeriodicalIF":40.6,"publicationDate":"2010-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2010-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4815104","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}

引用次数: 46

Interferometer Techniques for Gravitational-Wave Detection 引力波探测的干涉仪技术

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2010-02-25 DOI: 10.12942/lrr-2010-1

Andreas Freise, Kenneth Strain

引用次数: 59

Physics, Astrophysics and Cosmology with Gravitational Waves 物理学，天体物理学和宇宙学与引力波

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2009-12-01 DOI: 10.12942/lrr-2009-2

B. S. Sathyaprakash, Bernard F. Schutz

引用次数: 669

On Special Optical Modes and Thermal Issues in Advanced Gravitational Wave Interferometric Detectors 先进引力波干涉探测器的特殊光学模式和热问题

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2009-12-01 DOI: 10.12942/lrr-2009-5

Jean-Yves Vinet

引用次数: 38

Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation 零测地线同余、渐近平坦时空及其物理解释

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2009-09-11 DOI: 10.12942/lrr-2009-6

Timothy M. Adamo, Carlos Kozameh, Ezra T. Newman

{"title":"Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation","authors":"Timothy M. Adamo, Carlos Kozameh, Ezra T. Newman","doi":"10.12942/lrr-2009-6","DOIUrl":"https://doi.org/10.12942/lrr-2009-6","url":null,"abstract":"A priori, there is nothing very special about shear-free or asymptotically shear-free null geodesic congruences. Surprisingly, however, they turn out to possess a large number of fascinating geometric properties and to be closely related, in the context of general relativity, to a variety of physically significant effects. It is the purpose of this paper to try to fully develop these issues.This work starts with a detailed exposition of the theory of shear-free and asymptotically shear-free null geodesic congruences, i.e., congruences with shear that vanishes at future conformal null infinity. A major portion of the exposition lies in the analysis of the space of regular shear-free and asymptotically shear-free null geodesic congruences. This analysis leads to the space of complex analytic curves in an auxiliary four-complex dimensional space, ({mathcal H})-space. They in turn play a dominant role in the applications.The applications center around the problem of extracting interior physical properties of an asymptotically-flat spacetime directly from the asymptotic gravitational (and Maxwell) field itself, in analogy with the determination of total charge by an integral over the Maxwell field at infinity or the identification of the interior mass (and its loss) by (Bondi’s) integrals of the Weyl tensor, also at infinity.More specifically, we will see that the asymptotically shear-free congruences lead us to an asymptotic definition of the center-of-mass and its equations of motion. This includes a kinematic meaning, in terms of the center-of-mass motion, for the Bondi three-momentum. In addition, we obtain insights into intrinsic spin and, in general, angular momentum, including an angular-momentum-conservation law with well-defined flux terms. When a Maxwell field is present, the asymptotically shear-free congruences allow us to determine/define at infinity a center-of-charge world line and intrinsic magnetic dipole moment.","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":null,"pages":null},"PeriodicalIF":40.6,"publicationDate":"2009-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12942/lrr-2009-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4475730","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}

引用次数: 90

Quasi-Local Energy-Momentum and Angular Momentum in General Relativity 广义相对论中的准局部能量动量和角动量

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2009-06-19 DOI: 10.12942/lrr-2009-4

László B. Szabados

引用次数: 278

Characteristic Evolution and Matching 特征演化与匹配

IF 40.6 2区物理与天体物理

Living Reviews in Relativity Pub Date : 2009-04-16 DOI: 10.12942/lrr-2009-3

Jeffrey Winicour

引用次数: 142