Classical and Quantum Gravity最新文献

{"title":"The first law and weak cosmic censorship for de Sitter black holes","authors":"Daisuke Yoshida and Kaho Yoshimura","doi":"10.1088/1361-6382/add787","DOIUrl":"https://doi.org/10.1088/1361-6382/add787","url":null,"abstract":"We apply Iyer–Wald’s covariant phase space formalism to asymptotically de Sitter spacetimes and establish the thermodynamic first law, expressed in terms of the Abbott–Deser mass. Similar to Iyer–Wald’s first law for asymptotically flat black holes, our first law applies to general asymptotically de Sitter perturbations around a Reissner–Nordström–de Sitter black hole, without imposing any symmetry for the perturbations. We explicitly derive the first law up to the second order in perturbation. Additionally, we apply this first law to a thought experiment involving the overcharging of a Reissner–Nordström–de Sitter black hole by injecting energy and charge sources. We find that asymptotically de Sitter black holes cannot be overcharged, provided that the null energy condition holds, thereby reinforcing the weak cosmic censorship conjecture.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"134 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130136","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":"Accelerating numerical relativity with code generation: CUDA-enabled hyperbolic relaxation","authors":"Samuel D Tootle, Leonardo R Werneck, Thiago Assumpção, Terrence Pierre Jacques and Zachariah B Etienne","doi":"10.1088/1361-6382/add63e","DOIUrl":"https://doi.org/10.1088/1361-6382/add63e","url":null,"abstract":"Next-generation gravitational wave (GW) detectors such as Cosmic Explorer, the Einstein Telescope, and LISA, demand highly accurate and extensive GW catalogs to faithfully extract physical parameters from observed signals. However, numerical relativity (NR) faces significant challenges in generating these catalogs at the required scale and accuracy on modern computers, as NR codes do not fully exploit modern GPU capabilities. In response, we extend NRPy, a Python-based NR code-generation framework, to develop NRPyEllipticGPU—a CUDA-optimized elliptic solver tailored for the binary black hole initial data problem. NRPyEllipticGPU is the first GPU-enabled elliptic solver in the NR community, supporting a variety of coordinate systems and demonstrating substantial performance improvements on both consumer-grade and HPC-grade GPUs. We show that, when compared to a high-end CPU, NRPyEllipticGPU achieves on a high-end GPU up to a sixteenfold speedup in single precision while increasing double-precision performance by a factor of 2–4. This performance boost leverages the GPU’s superior parallelism and memory bandwidth to achieve a compute-bound application and enhancing the overall simulation efficiency. As NRPyEllipticGPU shares the core infrastructure common to NR codes, this work serves as a practical guide for developing full, CUDA-optimized NR codes.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"4 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113981","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":"On the global Gaussian bending measure and its applications in stationary spacetimes","authors":"Zhen Zhang and Rui Zhang","doi":"10.1088/1361-6382/add788","DOIUrl":"https://doi.org/10.1088/1361-6382/add788","url":null,"abstract":"Modified gravity theories have been suggested to address the limitations of general relativity (GR), each exhibiting differences, particularly in their strong-field limits. Nonetheless, there lacks effective means to distinguish or test these theories through local strong-field measurements. In this work, we define a global Gaussian bending measure over singular spacetime regions, establish a corresponding global theory, and demonstrate its applications in a general stationary spacetime. The global theory is based on differential geometry, rather than on specific gravity theories, allowing it to depict various physics within GR and beyond. For example, it can be applied to describe the gravitational bending of massless or massive messengers, such as photons, neutrinos, cosmic rays, and possibly massive gravitational waves predicted in certain theories of gravity. Besides, the global theory is applicable to any stationary spacetime regions outside a rotating black hole. As an instance of its direct applications, we investigate the highly-curved spacetime effects of the black hole in its immediate surrounding regions and design local strong-field experiments involving different shapes of singular lensing patches. New means can be therefore anticipated to be developed according to the global theory to differentiate between different gravity theories and test them in their strong-field regions.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"16 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114005","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":"Bose–Einstein condensates near charged noncommutative inspired black holes","authors":"Shukhrat Mardonov, Javlon Rayimbaev, Farukh Abdulkhamidov, Eldor Karimbaev and Bakhrom Abdulazizov","doi":"10.1088/1361-6382/adcb83","DOIUrl":"https://doi.org/10.1088/1361-6382/adcb83","url":null,"abstract":"In the present work, we investigate the Bose–Einstein condensates (BECs) on electrically charged noncommutative-inspired (NCi) black holes (BHs). The NC parameter represents a quantum correction that modifies spacetime geometry by introducing a minimal length scale. This impacts the BH’s effective gravitational field and, consequently, the dynamics of nearby scalar fields. The BEC is represented by a massive scalar field governed by the Klein–Gordon equation with a self-interaction term, assuming the scalar field is uncharged and devoid of self-gravitation and the mass parameter of the scalar field to be sufficiently small that may allow conditions to be a candidate for dark-matter clouds. We start our study by analyzing the properties of the event horizon and the mass profiles of NCi BH inside it. The BH charge and the NC parameters, , space are also studied. Then, we analyze the effective potential of a test scalar field in both radial and tortoise coordinates for the different values of the BH charge, the NC, and the scalar field mass parameters. Finally, we study the density function in the Thomas–Fermi approximation, in which the condensate is located in a spherical shell. The parameters Q and Θ can slightly modify the condensed density distribution.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"8 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104581","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":"Optimal design of interpolation methods for time-delay interferometry","authors":"Martin Staab, Jean-Baptiste Bayle, Olaf Hartwig, Aurélien Hees, Marc Lilley, Graham Woan and Peter Wolf","doi":"10.1088/1361-6382/add706","DOIUrl":"https://doi.org/10.1088/1361-6382/add706","url":null,"abstract":"Time-delay interferometry (TDI) suppresses laser frequency noise by forming linear combinations of time-shifted interferometric measurements. The time-shift operation is implemented by interpolating discretely sampled data. To enable in-band laser noise reduction by eight to nine orders of magnitude, interpolation has to be performed with high accuracy. Interpolation can be understood as the convolution of an interpolation kernel with the data to be shifted. Optimizing the design of this interpolation kernel is the focus of this work. Previous research that studied constant time-shifts suggested Lagrange interpolation as the interpolation method for TDI. Its transfer function is maximally flat at DC and therefore performs well at low frequency. However, to be accurate at high frequencies, Lagrange interpolation requires a high number of coefficients. Furthermore, when applied in TDI we observed prominent time-domain features when a time-varying shift scanned over a pure integer sample shift. To limit this effect we identify an additional requirement for the interpolation kernel: when considering time-varying shifts the interpolation kernel must be sufficiently smooth to avoid unwanted time-domain transitions that produce glitch-like features in power spectral density estimates. The Lagrange interpolation kernel exhibits a discontinuous first derivative by construction, which is insufficient for the application to LISA or other space-based gravitational-wave observatories. As a solution we propose a novel design method for interpolation kernels that respect a predefined requirement on in-band interpolation residuals and that possess continuous derivatives up to a prescribed order. Using this method we show that an interpolation kernel with 22 coefficients is sufficient to respect LISA’s picometre-requirement and to allow for a continuous first derivative which suppresses the magnitude of the time-domain transition adequately. The reduction from 42 (Lagrange interpolation) to 22 coefficients enables us to increase robustness against artifacts in the data and, as a side effect, save computational cost.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"129 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104583","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":"The exact Wheeler–DeWitt equation for the scale-factor minisuperspace model","authors":"Eftychios Kaimakkamis, Hervé Partouche, Karunava Sil and Nicolaos Toumbas","doi":"10.1088/1361-6382/add705","DOIUrl":"https://doi.org/10.1088/1361-6382/add705","url":null,"abstract":"We consider the classical minisuperspace model describing a closed, homogeneous and isotropic Universe, with a positive cosmological constant. Upon canonical quantization, the infinite number of possible operator orderings in the quantum Hamiltonian leads to distinct Wheeler–DeWitt (WDW) equations for the wavefunction ψ of the Universe. Similarly, ambiguity arises in the path-integral formulation of ψ, due to the infinite choices of path-integral measures for the single degree of freedom of the model. For each choice of path-integral measure, we determine the correct operator ordering of the quantum Hamiltonian and derive the exact form of the WDW equation, including all corrections in . Additionally, we impose Hermiticity of the Hamiltonian to deduce the Hilbert-space measure µ, which appears in the definition of the Hermitian inner product. Remarkably, all quantum predictions can be expressed through the combination , which satisfies a universal WDW equation, independent of the initial path-integral prescription. This result demonstrates that all seemingly distinct quantum theories arising from different quantization schemes of the same classical model are fundamentally equivalent.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"55 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104582","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":"Parameter estimation from the core-bounce phase of rotating core collapse supernovae in real interferometer noise","authors":"L O Villegas, C Moreno, M A Pajkos, M Zanolin and J M Antelis","doi":"10.1088/1361-6382/add235","DOIUrl":"https://doi.org/10.1088/1361-6382/add235","url":null,"abstract":"We develop and characterize a parameter estimation methodology for rotating core collapse supernovae based on the gravitational wave (GW) core bounce phase and real detector noise. Expanding on the evidence from numerical simulations for the deterministic nature of this GW emission and about the dependence on the ratio β between rotational kinetic to potential energy, we propose an analytical model for the core bounce component which depends on β and one phenomenological parameter. We validate the goodness of the model with a pool of representative waveforms. We use the fitting factor adopted in compact coalescing binary searches as a metric to quantify the goodness of the analytical model and the template bank generated by the model presents an average accuracy of 94.4% when compared with the numerical simulations and is used as the basis for the work. The error for a matched filter frequentist parameter estimation of β is evaluated. The results obtained considering real interferometric noise and a waveform at a distance of 10 kpc and optimal orientation, for one standard deviation estimation error of the rotation parameter β lie in the range of 10−2–10−3 as β increases. The results are also compared to the scenario where Gaussian recolored data is employed. The analytical model also allows for the first time, to compute theoretical minima in the error for β for any type of estimator. Our analysis indicates that the presence of rotation would be detectable at 0.5 Mpc for third generation interferometers like CE or ET.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"41 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097611","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":"Intrinsic torsion, extrinsic torsion, and the Hubble parameter","authors":"Brett McInnes","doi":"10.1088/1361-6382/add463","DOIUrl":"https://doi.org/10.1088/1361-6382/add463","url":null,"abstract":"We study the intrinsic and extrinsic torsions (defined by analogy with the intrinsic and extrinsic curvatures) of the spatial sections of torsional spacetimes. We consider two possibilities. First, that the intrinsic torsion might prove to be directly observable. Second, that it is not observable, having been ‘inflated away’ in the early Universe. We argue that, even in this second case, the extrinsic torsion may grow during the inflationary era and be non-negligible at reheating and thereafter. Even if the spatial intrinsic curvature and torsion are too small to be detected directly, then, the extrinsic torsion might not be. We point out that, if its presence is not recognised, the extrinsic torsion could lead to anomalies in the theoretical estimate of the Hubble parameter—a result with obvious potential applications. We stress that extrinsic torsion is by far the most natural way to produce such anomalies, simply because it mixes naturally with the Hubble parameter; that is, the second fundamental form of a spacelike section depends on a sum of two terms, one determined by the Hubble parameter, the other by the extrinsic torsion.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"25 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088297","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":"A note on strong cosmic censorship and its violation in Reissner–Nordström de Sitter black hole space-times","authors":"Anna Chrysostomou, Alan S Cornell, Aldo Deandrea and Seong Chan Park","doi":"10.1088/1361-6382/add5b4","DOIUrl":"https://doi.org/10.1088/1361-6382/add5b4","url":null,"abstract":"Penrose’s strong cosmic censorship (SCC) conjecture safeguards determinism in general relativity (GR). Within the initial value approach to GR, proof of SCC preservation is predicated on the unique evolution of the metric. For the Kerr–Newman family of black hole solutions, this requires the inextendibility of the metric past the Cauchy horizon, due to the development of a ‘blue-shift’ instability. Attempts to provide a rigorous mathematical proof of SCC has led to the formulation of several SCC conjectures of varying strengths, which seem to be discussed rarely outside of the mathematical relativity literature. In this note, we review some of the arguments for and against SCC preservation, with a focus on the Reissner–Nordström de Sitter (RNdS) context, where the positive cosmological constant invites a ‘red-shift’ effect that competes against the ‘blue-shift’. We study the consequent role of quasinormal mode behaviour and illustrate the parameter space for which we consistently observe violations of the SCC conjecture within RNdS black holes.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"151 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088270","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":"Classical and quantum trace-free Einstein cosmology","authors":"Merced Montesinos, Abdel Pérez-Lorenzana, Jorge Meza and Diego Gonzalez","doi":"10.1088/1361-6382/add5b5","DOIUrl":"https://doi.org/10.1088/1361-6382/add5b5","url":null,"abstract":"Trace-free Einstein gravity, in the absence of matter fields and using the Friedmann–Robertson–Walker (FRW) metric, is solvable both classically and quantum mechanically. This is achieved by using the conformal time as the time variable and the negative or positive of the inverse of the scale factor as configuration variable to write the classical equation of motion, which turns out to be the one of a free particle (k = 0), a harmonic oscillator (k = 1), and a repulsive oscillator ( ) in the real half-line. In all cases, the observable identified as the cosmological constant is six times the Hamiltonian. In particular, for a closed Universe (k = 1), spacetime exhibits a cyclic evolution along which the scalar curvature is constant and finite, thereby avoiding singularities. The quantum theory is reached by using canonical quantization. We calculate the spectrum of the observable corresponding to the cosmological constant. Remarkably, for the closed Universe (k = 1), the spectrum is discrete and positive while for flat (k = 0) and open ( ) universes, the spectra are continuous. Heisenberg’s uncertainty principle imposes limitations on the simultaneous measurement of the Hubble expansion (momentum variable) and the configuration variable. We also report the observable identified as the cosmological constant for inflaton, phantom and perfect fluids coupled to trace-free Einstein gravity in the FRW metric.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"55 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088271","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}