Living Reviews in Relativity最新文献

{"title":"Dynamical boson stars","authors":"Steven L. Liebling,&nbsp;Carlos Palenzuela","doi":"10.1007/s41114-023-00043-4","DOIUrl":"10.1007/s41114-023-00043-4","url":null,"abstract":"<div><p>The idea of stable, localized bundles of energy has strong appeal as a model for particles. In the 1950s, John Wheeler envisioned such bundles as smooth configurations of electromagnetic energy that he called <i>geons</i>, but none were found. Instead, particle-like solutions were found in the late 1960s with the addition of a scalar field, and these were given the name <i>boson stars</i>. Since then, boson stars find use in a wide variety of models as sources of dark matter, as black hole mimickers, in simple models of binary systems, and as a tool in finding black holes in higher dimensions with only a single Killing vector. We discuss important varieties of boson stars, their dynamic properties, and some of their uses, concentrating on recent efforts.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"26 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-023-00043-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4929595","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":"Unveiling the Universe with emerging cosmological probes","authors":"Michele Moresco,&nbsp;Lorenzo Amati,&nbsp;Luca Amendola,&nbsp;Simon Birrer,&nbsp;John P. Blakeslee,&nbsp;Michele Cantiello,&nbsp;Andrea Cimatti,&nbsp;Jeremy Darling,&nbsp;Massimo Della Valle,&nbsp;Maya Fishbach,&nbsp;Claudio Grillo,&nbsp;Nico Hamaus,&nbsp;Daniel Holz,&nbsp;Luca Izzo,&nbsp;Raul Jimenez,&nbsp;Elisabeta Lusso,&nbsp;Massimo Meneghetti,&nbsp;Ester Piedipalumbo,&nbsp;Alice Pisani,&nbsp;Alkistis Pourtsidou,&nbsp;Lucia Pozzetti,&nbsp;Miguel Quartin,&nbsp;Guido Risaliti,&nbsp;Piero Rosati,&nbsp;Licia Verde","doi":"10.1007/s41114-022-00040-z","DOIUrl":"10.1007/s41114-022-00040-z","url":null,"abstract":"<div><p>The detection of the accelerated expansion of the Universe has been one of the major breakthroughs in modern cosmology. Several cosmological probes (Cosmic Microwave Background, Supernovae Type Ia, Baryon Acoustic Oscillations) have been studied in depth to better understand the nature of the mechanism driving this acceleration, and they are being currently pushed to their limits, obtaining remarkable constraints that allowed us to shape the standard cosmological model. In parallel to that, however, the percent precision achieved has recently revealed apparent tensions between measurements obtained from different methods. These are either indicating some unaccounted systematic effects, or are pointing toward new physics. Following the development of CMB, SNe, and BAO cosmology, it is critical to extend our selection of cosmological probes. Novel probes can be exploited to validate results, control or mitigate systematic effects, and, most importantly, to increase the accuracy and robustness of our results. This review is meant to provide a state-of-art benchmark of the latest advances in emerging “beyond-standard” cosmological probes. We present how several different methods can become a key resource for observational cosmology. In particular, we review cosmic chronometers, quasars, gamma-ray bursts, standard sirens, lensing time-delay with galaxies and clusters, cosmic voids, neutral hydrogen intensity mapping, surface brightness fluctuations, stellar ages of the oldest objects, secular redshift drift, and clustering of standard candles. The review describes the method, systematics, and results of each probe in a homogeneous way, giving the reader a clear picture of the available innovative methods that have been introduced in recent years and how to apply them. The review also discusses the potential synergies and complementarities between the various probes, exploring how they will contribute to the future of modern cosmology.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-022-00040-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88668833","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":"Correction to: Gravitational wave detection by interferometry (ground and space)","authors":"Sheila Rowan,&nbsp;Jim Hough","doi":"10.1007/s41114-022-00039-6","DOIUrl":"10.1007/s41114-022-00039-6","url":null,"abstract":"","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2022-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-022-00039-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78723492","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":"New horizons for fundamental physics with LISA","authors":"K. G. Arun,&nbsp;Enis Belgacem,&nbsp;Robert Benkel,&nbsp;Laura Bernard,&nbsp;Emanuele Berti,&nbsp;Gianfranco Bertone,&nbsp;Marc Besancon,&nbsp;Diego Blas,&nbsp;Christian G. Böhmer,&nbsp;Richard Brito,&nbsp;Gianluca Calcagni,&nbsp;Alejandro Cardenas-Avendaño,&nbsp;Katy Clough,&nbsp;Marco Crisostomi,&nbsp;Valerio De Luca,&nbsp;Daniela Doneva,&nbsp;Stephanie Escoffier,&nbsp;José María Ezquiaga,&nbsp;Pedro G. Ferreira,&nbsp;Pierre Fleury,&nbsp;Stefano Foffa,&nbsp;Gabriele Franciolini,&nbsp;Noemi Frusciante,&nbsp;Juan García-Bellido,&nbsp;Carlos Herdeiro,&nbsp;Thomas Hertog,&nbsp;Tanja Hinderer,&nbsp;Philippe Jetzer,&nbsp;Lucas Lombriser,&nbsp;Elisa Maggio,&nbsp;Michele Maggiore,&nbsp;Michele Mancarella,&nbsp;Andrea Maselli,&nbsp;Sourabh Nampalliwar,&nbsp;David Nichols,&nbsp;Maria Okounkova,&nbsp;Paolo Pani,&nbsp;Vasileios Paschalidis,&nbsp;Alvise Raccanelli,&nbsp;Lisa Randall,&nbsp;Sébastien Renaux-Petel,&nbsp;Antonio Riotto,&nbsp;Milton Ruiz,&nbsp;Alexander Saffer,&nbsp;Mairi Sakellariadou,&nbsp;Ippocratis D. Saltas,&nbsp;B. S. Sathyaprakash,&nbsp;Lijing Shao,&nbsp;Carlos F. Sopuerta,&nbsp;Thomas P. Sotiriou,&nbsp;Nikolaos Stergioulas,&nbsp;Nicola Tamanini,&nbsp;Filippo Vernizzi,&nbsp;Helvi Witek,&nbsp;Kinwah Wu,&nbsp;Kent Yagi,&nbsp;Stoytcho Yazadjiev,&nbsp;Nicolás Yunes,&nbsp;Miguel Zilhão,&nbsp;Niayesh Afshordi,&nbsp;Marie-Christine Angonin,&nbsp;Vishal Baibhav,&nbsp;Enrico Barausse,&nbsp;Tiago Barreiro,&nbsp;Nicola Bartolo,&nbsp;Nicola Bellomo,&nbsp;Ido Ben-Dayan,&nbsp;Eric A. Bergshoeff,&nbsp;Sebastiano Bernuzzi,&nbsp;Daniele Bertacca,&nbsp;Swetha Bhagwat,&nbsp;Béatrice Bonga,&nbsp;Lior M. Burko,&nbsp;Geoffrey Compére,&nbsp;Giulia Cusin,&nbsp;Antonio da Silva,&nbsp;Saurya Das,&nbsp;Claudia de Rham,&nbsp;Kyriakos Destounis,&nbsp;Ema Dimastrogiovanni,&nbsp;Francisco Duque,&nbsp;Richard Easther,&nbsp;Hontas Farmer,&nbsp;Matteo Fasiello,&nbsp;Stanislav Fisenko,&nbsp;Kwinten Fransen,&nbsp;Jörg Frauendiener,&nbsp;Jonathan Gair,&nbsp;László Árpád Gergely,&nbsp;Davide Gerosa,&nbsp;Leonardo Gualtieri,&nbsp;Wen-Biao Han,&nbsp;Aurelien Hees,&nbsp;Thomas Helfer,&nbsp;Jörg Hennig,&nbsp;Alexander C. Jenkins,&nbsp;Eric Kajfasz,&nbsp;Nemanja Kaloper,&nbsp;Vladimír Karas,&nbsp;Bradley J. Kavanagh,&nbsp;Sergei A. Klioner,&nbsp;Savvas M. Koushiappas,&nbsp;Macarena Lagos,&nbsp;Christophe Le Poncin-Lafitte,&nbsp;Francisco S. N. Lobo,&nbsp;Charalampos Markakis,&nbsp;Prado Martín-Moruno,&nbsp;C. J. A. P. Martins,&nbsp;Sabino Matarrese,&nbsp;Daniel R. Mayerson,&nbsp;José P. Mimoso,&nbsp;Johannes Noller,&nbsp;Nelson J. Nunes,&nbsp;Roberto Oliveri,&nbsp;Giorgio Orlando,&nbsp;George Pappas,&nbsp;Igor Pikovski,&nbsp;Luigi Pilo,&nbsp;Jiří Podolský,&nbsp;Geraint Pratten,&nbsp;Tomislav Prokopec,&nbsp;Hong Qi,&nbsp;Saeed Rastgoo,&nbsp;Angelo Ricciardone,&nbsp;Rocco Rollo,&nbsp;Diego Rubiera-Garcia,&nbsp;Olga Sergijenko,&nbsp;Stuart Shapiro,&nbsp;Deirdre Shoemaker,&nbsp;Alessandro Spallicci,&nbsp;Oleksandr Stashko,&nbsp;Leo C. Stein,&nbsp;Gianmassimo Tasinato,&nbsp;Andrew J. Tolley,&nbsp;Elias C. Vagenas,&nbsp;Stefan Vandoren,&nbsp;Daniele Vernieri,&nbsp;Rodrigo Vicente,&nbsp;Toby Wiseman,&nbsp;Valery I. Zhdanov,&nbsp;Miguel Zumalacárregui","doi":"10.1007/s41114-022-00036-9","DOIUrl":"10.1007/s41114-022-00036-9","url":null,"abstract":"<div><p>The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about the fundamental theory of nature at play in the extreme gravity regime, where the gravitational interaction is both strong and dynamical. In this white paper, the Fundamental Physics Working Group of the LISA Consortium summarizes the current topics in fundamental physics where LISA observations of gravitational waves can be expected to provide key input. We provide the briefest of reviews to then delineate avenues for future research directions and to discuss connections between this working group, other working groups and the consortium work package teams. These connections must be developed for LISA to live up to its science potential in these areas.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-022-00036-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81305681","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":"Electromagnetic counterparts to massive black-hole mergers","authors":"Tamara Bogdanović,&nbsp;M. Coleman Miller,&nbsp;Laura Blecha","doi":"10.1007/s41114-022-00037-8","DOIUrl":"10.1007/s41114-022-00037-8","url":null,"abstract":"<div><p>The next two decades are expected to open the door to the first coincident detections of electromagnetic (EM) and gravitational-wave (GW) signatures associated with massive black-hole (MBH) binaries heading for coalescence. These detections will launch a new era of multimessenger astrophysics by expanding this growing field to the low-frequency GW regime and will provide an unprecedented understanding of the evolution of MBHs and galaxies. They will also constitute fundamentally new probes of cosmology and would enable unique tests of gravity. The aim of this Living Review is to provide an introduction to this research topic by presenting a summary of key findings, physical processes and ideas pertaining to EM counterparts to MBH mergers as they are known at the time of this writing. We review current observational evidence for close MBH binaries, discuss relevant physical processes and timescales, and summarize the possible EM counterparts to GWs in the precursor, coalescence, and afterglow stages of a MBH merger. We also describe open questions and discuss future prospects in this dynamic and quick-paced research area.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9232481/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10433206","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":"Reduced order and surrogate models for gravitational waves","authors":"Manuel Tiglio,&nbsp;Aarón Villanueva","doi":"10.1007/s41114-022-00035-w","DOIUrl":"10.1007/s41114-022-00035-w","url":null,"abstract":"<div><p>We present an introduction to some of the state of the art in reduced order and surrogate modeling in gravitational-wave (GW) science. Approaches that we cover include principal component analysis, proper orthogonal (singular value) decompositions, the reduced basis approach, the empirical interpolation method, reduced order quadratures, and compressed likelihood evaluations. We divide the review into three parts: representation/compression of known data, predictive models, and data analysis. The targeted audience is practitioners in GW science, a field in which building predictive models and data analysis tools that are both accurate and fast to evaluate, especially when dealing with large amounts of data and intensive computations, are necessary yet can be challenging. As such, practical presentations and, sometimes, heuristic approaches are here preferred over rigor when the latter is not available. This review aims to be self-contained, within reasonable page limits, with little previous knowledge (at the undergraduate level) requirements in mathematics, scientific computing, and related disciplines. Emphasis is placed on optimality, as well as the curse of dimensionality and approaches that might have the promise of beating it. We also review most of the state of the art of GW surrogates. Some numerical algorithms, conditioning details, scalability, parallelization and other practical points are discussed. The approaches presented are to a large extent non-intrusive (in the sense that no differential equations are invoked) and data-driven and can therefore be applicable to other disciplines. We close with open challenges in high dimension surrogates, which are not unique to GW science.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-022-00035-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77995215","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":"Rates of compact object coalescences","authors":"Ilya Mandel,&nbsp;Floor S. Broekgaarden","doi":"10.1007/s41114-021-00034-3","DOIUrl":"10.1007/s41114-021-00034-3","url":null,"abstract":"<div><p>Gravitational-wave detections are enabling measurements of the rate of coalescences of binaries composed of two compact objects—neutron stars and/or black holes. The coalescence rate of binaries containing neutron stars is further constrained by electromagnetic observations, including Galactic radio binary pulsars and short gamma-ray bursts. Meanwhile, increasingly sophisticated models of compact objects merging through a variety of evolutionary channels produce a range of theoretically predicted rates. Rapid improvements in instrument sensitivity, along with plans for new and improved surveys, make this an opportune time to summarise the existing observational and theoretical knowledge of compact-binary coalescence rates.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"25 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2022-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-021-00034-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4678184","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":"Challenges and opportunities of gravitational-wave searches at MHz to GHz frequencies","authors":"Nancy Aggarwal,&nbsp;Odylio D. Aguiar,&nbsp;Andreas Bauswein,&nbsp;Giancarlo Cella,&nbsp;Sebastian Clesse,&nbsp;Adrian Michael Cruise,&nbsp;Valerie Domcke,&nbsp;Daniel G. Figueroa,&nbsp;Andrew Geraci,&nbsp;Maxim Goryachev,&nbsp;Hartmut Grote,&nbsp;Mark Hindmarsh,&nbsp;Francesco Muia,&nbsp;Nikhil Mukund,&nbsp;David Ottaway,&nbsp;Marco Peloso,&nbsp;Fernando Quevedo,&nbsp;Angelo Ricciardone,&nbsp;Jessica Steinlechner,&nbsp;Sebastian Steinlechner,&nbsp;Sichun Sun,&nbsp;Michael E. Tobar,&nbsp;Francisco Torrenti,&nbsp;Caner Ünal,&nbsp;Graham White","doi":"10.1007/s41114-021-00032-5","DOIUrl":"10.1007/s41114-021-00032-5","url":null,"abstract":"<div><p>The first direct measurement of gravitational waves by the LIGO and Virgo collaborations has opened up new avenues to explore our Universe. This white paper outlines the challenges and gains expected in gravitational-wave searches at frequencies above the LIGO/Virgo band, with a particular focus on Ultra High-Frequency Gravitational Waves (UHF-GWs), covering the MHz to GHz range. The absence of known astrophysical sources in this frequency range provides a unique opportunity to discover physics beyond the Standard Model operating both in the early and late Universe, and we highlight some of the most promising gravitational sources. We review several detector concepts that have been proposed to take up this challenge, and compare their expected sensitivity with the signal strength predicted in various models. This report is the summary of the workshop “Challenges and opportunities of high-frequency gravitational wave detection” held at ICTP Trieste, Italy in October 2019, that set up the stage for the recently launched Ultra-High-Frequency Gravitational Wave (UHF-GW) initiative.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"24 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-021-00032-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72975674","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":"Coalescence of black hole–neutron star binaries","authors":"Koutarou Kyutoku,&nbsp;Masaru Shibata,&nbsp;Keisuke Taniguchi","doi":"10.1007/s41114-021-00033-4","DOIUrl":"10.1007/s41114-021-00033-4","url":null,"abstract":"<div><p>We review the current status of general relativistic studies for coalescences of black hole–neutron star binaries. First, high-precision computations of black hole–neutron star binaries in quasiequilibrium circular orbits are summarized, focusing on the quasiequilibrium sequences and the mass-shedding limit. Next, the current status of numerical-relativity simulations for the merger of black hole–neutron star binaries is described. We summarize our understanding for the merger process, tidal disruption and its criterion, properties of the merger remnant and ejected material, gravitational waveforms, and gravitational-wave spectra. We also discuss expected electromagnetic counterparts to black hole–neutron star coalescences.</p></div>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"24 1","pages":""},"PeriodicalIF":26.3,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s41114-021-00033-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90321683","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 fluid dynamics: physics for many different scales","authors":"Nils Andersson,&nbsp;Gregory L. Comer","doi":"10.1007/s41114-021-00031-6","DOIUrl":"https://doi.org/10.1007/s41114-021-00031-6","url":null,"abstract":"<p>The relativistic fluid is a highly successful model used to describe the dynamics of many-particle systems moving at high velocities and/or in strong gravity. It takes as input physics from microscopic scales and yields as output predictions of bulk, macroscopic motion. By inverting the process—e.g., drawing on astrophysical observations—an understanding of relativistic features can lead to insight into physics on the microscopic scale. Relativistic fluids have been used to model systems as “small” as colliding heavy ions in laboratory experiments, and as large as the Universe itself, with “intermediate” sized objects like neutron stars being considered along the way. The purpose of this review is to discuss the mathematical and theoretical physics underpinnings of the relativistic (multi-) fluid model. We focus on the variational principle approach championed by Brandon Carter and collaborators, in which a crucial element is to distinguish the momenta that are conjugate to the particle number density currents. This approach differs from the “standard” text-book derivation of the equations of motion from the divergence of the stress-energy tensor in that one explicitly obtains the relativistic Euler equation as an “integrability” condition on the relativistic vorticity. We discuss the conservation laws and the equations of motion in detail, and provide a number of (in our opinion) interesting and relevant applications of the general theory. The formalism provides a foundation for complex models, e.g., including electromagnetism, superfluidity and elasticity—all of which are relevant for state of the art neutron-star modelling.</p>","PeriodicalId":686,"journal":{"name":"Living Reviews in Relativity","volume":"24 1","pages":""},"PeriodicalIF":40.6,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s41114-021-00031-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4935348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}