Classical and Quantum Gravity最新文献

{"title":"A note on the conversion of orbital angles for extreme mass ratio inspirals","authors":"Philip Lynch and Ollie Burke","doi":"10.1088/1361-6382/adf02b","DOIUrl":"https://doi.org/10.1088/1361-6382/adf02b","url":null,"abstract":"We outline a practical scheme for converting between three commonly used sets of phases to describe the trajectories of extreme mass ratio inspirals; quasi-Keplerian (QK) angles, Mino time (MT) action-angles, and Boyer–Lindquist (BL) time action-angles (as utilised by the FastEMRIWaveform package). Conversion between BL time action angles (AAs) and QK angles is essential for the construction of a source frame for adiabatic inspirals that can be related to the source frames used by other gravitational wave source modelling techniques. While converting from QK angles to BL time AAs via MT action-angles can be done analytically, the same does not hold for the converse, and so we make use of an efficient numerical root-finding method. We demonstrate the efficacy of our scheme by comparing two calculations for an eccentric and inclined geodesic orbit in Kerr spacetime using two different sets of orbital angles. We have made our implementations available in Mathematica, C, and Python.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"19 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144819503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"GWSpace: a multi-mission science data simulator for space-based gravitational wave detection","authors":"En-Kun Li, Han Wang, Hong-Yu Chen, Huimin Fan, Ya-Nan Li, Zhi-Yuan Li, Zheng-Cheng Liang, Xiang-Yu Lyu, Tian-Xiao Wang, Zheng Wu, Chang-Qing Ye, Xue-Ting Zhang, Yiming Hu and Jianwei Mei","doi":"10.1088/1361-6382/adf409","DOIUrl":"https://doi.org/10.1088/1361-6382/adf409","url":null,"abstract":"Space-based gravitational wave detectors such as TianQin, laser interferometer space antenna (LISA), and Taiji have the potential to outperform themselves through joint observation. To achieve this, it is desirable to practice joint data analysis in advance on simulated data that encodes the intrinsic correlation among the signals found in different detectors that operate simultaneously. In this paper, we introduce GWSpace, a package that can simulate the joint detection data from TianQin, LISA, and Taiji. The software is not a groundbreaking work that starts from scratch. Rather, we use as many open-source resources as possible, tailoring them to the needs of simulating the multi-mission science data and putting everything into a ready-to-go and easy-to-use package. We shall describe the main components, the construction, and a few examples of application of the package. A common coordinate system, namely the Solar System barycenter coordinate system, is utilized to calculate spacecraft orbits for all three missions. The paper also provides a brief derivation of the detection process and outlines the general waveform of sources detectable by these detectors.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"18 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144819504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Generators of local Lorentz transformation in ADM-Vielbein formalism of gravitational relativity","authors":"Alireza Faraji, Zahra Molaee and Ahmad Shirzad","doi":"10.1088/1361-6382/adf0de","DOIUrl":"https://doi.org/10.1088/1361-6382/adf0de","url":null,"abstract":"General relativity contains 16 variables in the framework of ADM-Vielbein formalism, which are six more than in the metric formalism. These variables emerge due to the additional symmetry of local Lorentz transformations. In the framework of the Hamiltonian approach, it is expected to find first class constraints that generate this gauge symmetry. We introduce the complete form of such constraints and show that they exactly obey the algebra of the Lorentz group.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"68 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144796808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Inverted oscillators for testing gravity-induced quantum entanglement","authors":"Tomohiro Fujita, Youka Kaku, Akira Matsumura and Yuta Michimura","doi":"10.1088/1361-6382/adf0bb","DOIUrl":"https://doi.org/10.1088/1361-6382/adf0bb","url":null,"abstract":"In the quest for quantum gravity, we have lacked experimental verification, hampered by the weakness of gravity and decoherence. Recently, various experiments have been proposed to verify quantum entanglement induced by Newtonian gravitational interactions. However, they are not yet certainly feasible with existing techniques. To search for a new setup, we compute the logarithmic negativity of two oscillators with arbitrary quadratic potential coupled by gravity. We find that unstable inverted oscillators generate gravity-induced entanglement most efficiently and are most resistant to decoherence from environmental fluctuations. As an experimental realization, we propose a setup of the optical levitation of mirrors with the anti-spring effect. To avoid decoherence due to photon shot noise, a sandwich configuration that geometrically creates the anti-spring is promising.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"52 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144792277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Obstructions for trapped submanifolds","authors":"Gustavo Dotti","doi":"10.1088/1361-6382/adf2f1","DOIUrl":"https://doi.org/10.1088/1361-6382/adf2f1","url":null,"abstract":"We introduce the concept of future convex spacelike/null hypersurface Σ in an n + 1 dimensional spacetime M and prove that no dimensional closed trapped submanifold (k-CTM) can be tangent to Σ from its future side. As a consequence, k-CTMs cannot be found in open spacetime regions foliated by such hypersurfaces. In gravitational collapse scenarios, specific hypersurfaces of this kind act as past barriers for trapped submanifolds. A number of examples are worked out in detail, two of them showing 3 + 1 spacetime regions containing trapped loops (TLs) (k = 1) but no closed trapped surfaces (k = 2). The use of TLs as an early indicator of black hole formation is briefly discussed.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"6 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144786492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Connecting scattering, monodromy, and MST’s renormalized angular momentum for the Teukolsky equation in Kerr spacetime","authors":"Zachary Nasipak","doi":"10.1088/1361-6382/adf0df","DOIUrl":"https://doi.org/10.1088/1361-6382/adf0df","url":null,"abstract":"The Teukolsky equation describes perturbations of Kerr spacetime and is central to the study of rotating black holes and gravitational waves. In the frequency domain, the Teukolsky equation separates into radial and angular ordinary differential equations (ODEs). Mano, Suzuki, and Takasugi (MST) found semi-analytic solutions to the homogeneous radial Teukolsky equation in terms of series of analytic special functions. The MST expansions hinge on an auxiliary parameter known as the renormalized angular momentumν, which one must calculate to ensure the convergence of these series solutions. In this work, we present a method for calculating ν via monodromy eigenvalues, which capture the behavior of ODEs and their solutions in the complex domain near their singular points. We directly relate the monodromy data of the radial Teukolsky equation to the parameter ν and provide a numerical scheme for calculating ν based on monodromy. With this method we evaluate ν in different regions of parameter space and analyze the numerical stability of this approach. We also highlight how, through ν, monodromy data are linked to scattering amplitudes for generic (linear) perturbations of Kerr spacetime.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"54 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144778339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Spherical accretion of a collisionless kinetic gas into a generic static black hole","authors":"Mehrab Momennia and Olivier Sarbach","doi":"10.1088/1361-6382/adf0e0","DOIUrl":"https://doi.org/10.1088/1361-6382/adf0e0","url":null,"abstract":"We present a nontrivial extension of the problem of spherical accretion of a collisionless kinetic gas into the standard Schwarzschild black hole. This extension consists of replacing the Schwarzschild black hole by generic static and spherically symmetric black hole spacetimes with the aim of studying the effects of either modified gravitational theories beyond Einstein gravity or matter sources coupled to general relativity on the accretion process. This generalization also allows us to investigate the accretion into other types of black hole spacetimes, such as ones inspired by loop quantum gravity and string theory. To do so, we take into account a large class of static and spherically symmetric black holes whose spacetime is asymptotically flat with a positive total mass, has a regular Killing horizon, and satisfies appropriate monotonicity conditions of the metric functions. We provide the most general solution of the collisionless Boltzmann equation on such spacetimes by expressing the one-particle distribution function in terms of suitable symplectic coordinates on the cotangent bundle, and we calculate the relevant observables, such as particle current density and energy-momentum-stress tensor. Specializing to the case where the gas is described by an isotropic ideal fluid at rest at infinity, we compute the mass accretion rate and compression ratio, and we show that the tangential pressure is larger than the radial one at the horizon, indicating that the behavior of a collisionless gas is different from the one of an isotropic perfect fluid. Our general relations for the spacetime observables are given in terms of the generic metric functions which are determined by the parameters that characterize the black hole. As a concrete example, we apply our generic formulae to two special black hole spacetimes, namely the Reissner–Nordström black hole and a loop quantum corrected black hole. We explore the effects of the free parameters on the observables and accretion rate, and we compare the results with those corresponding to the standard Schwarzschild black hole.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"150 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"News tensor on null hypersurfaces","authors":"Francisco Fernández-Álvarez","doi":"10.1088/1361-6382/adf1d1","DOIUrl":"https://doi.org/10.1088/1361-6382/adf1d1","url":null,"abstract":"A geometric definition of news tensor on null hypersurfaces in four space-time dimensions is presented. When the conformal Einstein field equations hold, this news tensor yields the correct expression for the radiative components of the rescaled Weyl tensor at infinity with vanishing cosmological constant in arbitrary conformal gauge. Also, a generalised transport equation for the Geroch tensor is derived. Important differences between null hypersurfaces in the bulk of the space-time and null infinity with vanishing cosmological constant are reviewed, and their impact on the role of the news is discussed.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"26 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Impact of phase signal formulations on tilt-to-length coupling noise in the LISA test mass interferometer","authors":"Paul Edwards, Megha Dave, Alexander Weaver, Mengyuan Zhao, Paul Fulda, Guido Mueller and Gudrun Wanner","doi":"10.1088/1361-6382/addea4","DOIUrl":"https://doi.org/10.1088/1361-6382/addea4","url":null,"abstract":"Tilt-to-length (TTL) coupling in the Laser Interferometer Space Antenna (LISA) can generate spurious displacement noise that potentially affects the measurement of gravitational wave signals. In each test mass interferometer (TMIs), the coupling of misalignments with spacecraft angular jitter produces noise in the longitudinal pathlength signal. This signal comes from the phase readout combinations of an interfering measurement beam and a local reference beam at a quadrant photodetector, but various formulations exist for its calculation. Selection of this pathlength signal formulation affects the TTL coupling noise. We therefore simulated two pathlength signal candidates, the complex sum and the averaged phase, and evaluated their performance in the LISA TMI under the assumption of static alignment imperfections. All simulations were performed using three different methods with cross-checked results. We find with all three methods that the averaged phase is the choice with equal or less TTL coupling noise in four out of the five test cases. Finally, we show that the non-linear TTL contributions in the TMI to be negligible in all our test-cases, no matter which formulation of pathlength signal is chosen.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"111 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Free hyperboloidal evolution of the Einstein–Maxwell–Klein–Gordon system","authors":"João D Álvares and Alex Vaño-Viñuales","doi":"10.1088/1361-6382/adf0b9","DOIUrl":"https://doi.org/10.1088/1361-6382/adf0b9","url":null,"abstract":"We present simulations of the Einstein–Maxwell–Klein–Gordon system on compactified hyperboloidal slices. To the best of our knowledge, these are the first hyperboloidal evolutions of this system that employ a common formulation like BSSN/Z4. Hyperboloidal slices smoothly reach future null infinity, the only location in spacetime where radiation (such as gravitational waves) is unambiguously defined. We are thus able to reach null infinity and extract signals there. We showcase the capabilities of our implementation in spherical symmetry with the evolution of a charged scalar field perturbing a regular spacetime and near an electrically charged black hole. We also present the collapse of a charged scalar field into a Reissner–Nördstrom black hole. Here we show sample evolutions and validation tests for these setups.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"27 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}