Classical and Quantum Gravity最新文献_第5页

ERRATUM: Testing general covariance in effective models motivated by Loop Quantum Gravity 勘误：测试由环量子引力驱动的有效模型的一般协方差

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-21 DOI: 10.1088/1361-6382/aea516

Juan Carlos Del Águila,Hugo A Morales-Técotl

引用次数: 0

Scale-Dependent Weak-Field Dynamics in Horndeski Theory: Galaxy Rotation Curves and Turnaround Scales Horndeski理论中尺度相关的弱场动力学：星系旋转曲线和周转尺度

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-21 DOI: 10.1088/1361-6382/aeaabe

Hatice Özer

{"title":"Scale-Dependent Weak-Field Dynamics in Horndeski Theory: Galaxy Rotation Curves and Turnaround Scales","authors":"Hatice Özer","doi":"10.1088/1361-6382/aeaabe","DOIUrl":"https://doi.org/10.1088/1361-6382/aeaabe","url":null,"abstract":"Abstract In this work, the weak-field dynamics of a gravitational-wave compatible subclass of Horndeski gravity is investigated on galactic and intergalactic scales. The analysis is performed within the weak-field approximation for stationary and approximately spherically symmetric configurations, retaining the nonlinear scalar derivative interactions responsible for scale-dependent modifications of the gravitational field. On galactic scales, the transition regime is investigated through the effective potential, the stability of circular orbits, galaxy rotation curves, and the relation between dynamical and lensing masses. The analysis shows that the scalar field modifies the orbital dynamics and the radial dependence of the rotational velocity, while generating a nonvanishing gravitational slip between the dynamical and lensing mass estimates. On intergalactic scales, the asymptotic weak-field dynamics is investigated and a turnaround scale is derived from the balance between the effective gravitational attraction and the large-scale curvature contribution. At large distances, the asymptotic gravitational field is governed by the background curvature contribution.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"105 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020779","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}

引用次数: 0

Evaluating KAGRA upgrade scenarios for multimessenger observations of binary neutron stars 评估双中子星多信使观测的KAGRA升级方案

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-21 DOI: 10.1088/1361-6382/aeaa9c

Yuta Michimura,Soichiro Morisaki,Kenta Hotokezaka,Masaomi Tanaka

{"title":"Evaluating KAGRA upgrade scenarios for multimessenger observations of binary neutron stars","authors":"Yuta Michimura,Soichiro Morisaki,Kenta Hotokezaka,Masaomi Tanaka","doi":"10.1088/1361-6382/aeaa9c","DOIUrl":"https://doi.org/10.1088/1361-6382/aeaa9c","url":null,"abstract":"Abstract Binary neutron star mergers are key targets for multimessenger astronomy, motivating future upgrades of gravitational-wave detectors. For KAGRA, both broadband sensitivity improvements that increase the binary neutron star detection range, and high-frequency optimizations targeting neutron-star physics are under consideration. We present a computationally efficient framework to evaluate the multimessenger performance of detector upgrades by combining Fisher-matrix estimates of localization area and localization volume with detector duty factors and binary neutron star merger rates. We apply this framework to proposed KAGRA upgrade scenarios within the LIGO-Virgo-KAGRA network. For identical sources, inclusion of KAGRA improves sky localization by a factor of more than 5, with the high-frequency upgrade providing a further improvement of about 20% over the broadband option. However, when detection rates are taken into account, the broadband upgrade yields a larger number of well-localized events. Despite its shorter binary neutron star range than the other detectors, the inclusion of KAGRA increases the number of events localized within 10^3 Mpc}^3 volume by about 60%. These results provide a quantitative framework for evaluating future detector upgrades from the perspective of multimessenger observations.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"8 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020782","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}

引用次数: 0

Unitary and finite self-energy of a massive classical point charge as a naked point singularity 作为裸点奇点的大质量经典点电荷的幺正有限自能

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-18 DOI: 10.1088/1361-6382/aea9e6

Daxx William Delucchi

{"title":"Unitary and finite self-energy of a massive classical point charge as a naked point singularity","authors":"Daxx William Delucchi","doi":"10.1088/1361-6382/aea9e6","DOIUrl":"https://doi.org/10.1088/1361-6382/aea9e6","url":null,"abstract":"Abstract We analyze linear Einstein–Maxwell perturbations of the superextremal Reissner–Nordström geometry, the nonlinear self-field of a single static point charge, in its static Kerr–Schild rest frame. Using optical radial coordinates and gauge-invariant master variables, we reduce the radiative Einstein–Maxwell sectors to scalar wave equations on the half-line. The resulting master equations are of Regge–Wheeler type, with inverse-square potential cores at the optical apex and short-range tails at infinity. Hardy control at the apex, together with the short-range estimates at infinity, proves that the action-induced spatial T-energy forms are semibounded and closable. Closing these spatial forms determines their finite-energy configuration-form domains; adjoining the L² velocity components supplied by the kinetic energy gives the Cauchy-data energy spaces. The form representation theorem then yields the action-normalized Friedrichs Hamiltonians associated with the master operators. The static Coulomb field and its nonlinear gravitational backreaction are treated as the exact background. All radiative perturbations whose Cauchy data have finite total T-energy evolve uniquely and unitarily on the completed energy space. The naked singularity remains geometrically present but is dynamically silent: it carries no T-energy flux, supports no finite-energy bound state, and introduces no hidden finite-energy endpoint sector. We also construct the forward radiation field at future null infinity, obtaining a translation representation in which the conserved T-energy equals the squared L² norm of the radiation profile in retarded time.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"26 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149020777","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}

引用次数: 0

Finding and characterising physical states of Euclidean Abelianized loop quantum gravity using neural quantum states 利用神经量子态发现和表征欧几里得阿贝尔化环量子引力的物理状态

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5cb

Hanno Sahlmann,Waleed Sherif

{"title":"Finding and characterising physical states of Euclidean Abelianized loop quantum gravity using neural quantum states","authors":"Hanno Sahlmann,Waleed Sherif","doi":"10.1088/1361-6382/aea5cb","DOIUrl":"https://doi.org/10.1088/1361-6382/aea5cb","url":null,"abstract":"Abstract We study physical (near-kernel of constraints) states of 4-d Euclidean loop quantum gravity in Smolin's weak coupling limit on the complete graph $K_5$ using variational Monte Carlo with neural network quantum states. We investigate the Hamilton constraint $hat{H}$ in the ordering proposed by Thiemann, as well as $hat{H}^dagger$ and $hat{H}+hat{H}^dagger$. We find that the variational optimisation selects distinct solution families for $hat{H}$ and $hat{H}^dagger$ across several considered cutoffs on the kinematical degrees of freedom. The solution family of $hat{H}$ is flat on all minimal loops and has non-vanishing volume expectation values. Its edge-charge marginals delocalise with increasing cutoff, which indicates they are approximations to solutions that are non-normalisable in the kinematical inner product. The solution family for $hat{H}^dagger$ is normalisable, shows non-trivial charge correlations, lies in the kernel of volume and is not flat. $hat{H}+hat{H}^dagger$ turns out to be much harder to solve and yields quasi-solutions combining features of both previous families. We characterise all solutions using chromaticity 1- and 2-point functions, minimal loop holonomies, geometric area and volume operators and show that the two families can be interpreted as, on the one hand, a family of states close to the Ashtekar-Lewandowski vacuum and the Dittrich-Geiller vacuum with some numerical noise on the other hand. We also present some results that link solutions of the truncated theory to solutions of the continuum theory.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"35 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923315","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}

引用次数: 0

Tidal Forces in the Presence of Torsion and Nonmetricity 扭转和非对称存在下的潮汐力

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5c9

Armin van de Venn,Marcelo Netz-Marzola,David Vasak,Jürgen Struckmeier

引用次数: 0

Implication of dressed form of relational observable on von Neumann algebra 关系可观测值的修饰形式在冯·诺伊曼代数中的意义

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5c8

Min-Seok Seo

{"title":"Implication of dressed form of relational observable on von Neumann algebra","authors":"Min-Seok Seo","doi":"10.1088/1361-6382/aea5c8","DOIUrl":"https://doi.org/10.1088/1361-6382/aea5c8","url":null,"abstract":"Abstract In quantum gravity, a physically meaningful operator is required to be invariant under the diffeomorphisms. Such gauge invariant operator is typically given by the relational observable, the operator localized in relation to some background states. We point out that the relational observable can be comprehensively formulated as the dressed operator. For the background with a boundary where the diffeomorphisms are not gauged, we can use the gravitational Wilson line for dressing, then the relational observable is nonlocal. In contrast, when the background breaks some isometries, as can be found in quasi-de Sitter space, dressing can be local, implementing St\"uckelberg mechanism. Since dressing resembles the outer automorphism in the von Neumann algebra, we may investigate the algebraic structure of the background by considering the dressed form of the relational observable. From this, we can understand that quasi-de Sitter space is described by the Type II$_infty$ algebra where the trace diverges in the decoupling limit of gravity. It is different from the Type II$_1$ algebra of de Sitter space where the finite size of trace can be defined in the same limit. This shows that the isometry preserving and breaking backgrounds are quite different in the algebraic structure even in the decoupling limit of gravity.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"56 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923309","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}

引用次数: 0

Black Hole Thermodynamics via Tsallis Statistical Mechanics and Phase Transitions Probed by Optical Characteristics 基于Tsallis统计力学的黑洞热力学和光学特性探测的相变

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5ca

Phuwadon Chunaksorn,Ratchaphat Nakarachinda,Pitayuth Wongjun

{"title":"Black Hole Thermodynamics via Tsallis Statistical Mechanics and Phase Transitions Probed by Optical Characteristics","authors":"Phuwadon Chunaksorn,Ratchaphat Nakarachinda,Pitayuth Wongjun","doi":"10.1088/1361-6382/aea5ca","DOIUrl":"https://doi.org/10.1088/1361-6382/aea5ca","url":null,"abstract":"Abstract We establish a statistically grounded framework for generalized black hole thermodynamics based on non-extensive statistics. Unlike conventional phenomenological approaches, we explicitly derive a structurally unique generalized Bekenstein-Hawking entropy from the microscopic state counting of a near-horizon photon gas within the framework of Tsallis statistics. This formulation is fully consistent with the first law of black hole thermodynamics and smoothly recovers the standard Bekenstein-Hawking area law in the extensive limit (q → 1). To examine the macroscopic viability of this microscopically grounded entropy, we investigate its implications for Reissner-Nordström black holes. We demonstrate that the entropic deformation governs both local and global thermal stability, thereby generating a rich multi-branched phase structure comprising small, intermediate, and large black holes with Van der Waals-like critical behavior. We further establish an optical-thermodynamic analogy by relating photon-sphere observables, including orbital periods and Lyapunov exponents, to thermodynamic variables. These optical signatures qualitatively track the thermodynamic critical behavior and phase structure, suggesting their potential relevance as observational probes in future high-resolution measurements. Collectively, these results may shed light on a conceptual connection between non-extensive entropy, black-hole critical phenomena, and strong-gravity optics.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"12 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923310","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}

引用次数: 0

Impact of the equation of state on core collapse supernovae I: the low-T /|W | instability 状态方程对核心坍缩超新星的影响ⅰ：低t /|W |不稳定性

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5c7

Marco Cusinato,Martin Obergaulinger,Miguel Ángel Aloy

{"title":"Impact of the equation of state on core collapse supernovae I: the low-T /|W | instability","authors":"Marco Cusinato,Martin Obergaulinger,Miguel Ángel Aloy","doi":"10.1088/1361-6382/aea5c7","DOIUrl":"https://doi.org/10.1088/1361-6382/aea5c7","url":null,"abstract":"Abstract Rapidly rotating core-collapse supernovae are promising sources of multimessenger emission, as non-axisymmetric dynamics in the newly formed proto-neutron star can leave characteristic imprints on both gravitational waves and neutrinos. We present three-dimensional neutrino-magnetohydrodynamics simulations of the collapse of a rapidly rotating 35 M⊙ progenitor, performed with five different finite-temperature nuclear equations of state, to investigate how dense-matter physics affects the development of the low-T /|W | instability and its associated multimessenger signatures.&#xD;We find that the low-T /|W | instability develops in all equation of state models considered, indicating that its occurrence is robust for this rapidly rotating progenitor. However, its onset time, dominant azimuthal structure, lifetime, and characteristic multimessenger frequencies vary among models, reflecting differences in the evolving proto-neutron star structure and rotation profile. The instability produces large-scale spiral modes that generate quasi-periodic gravitational wave emission and modulate the neutrino luminosities, especially along directions close to the equatorial plane.&#xD;The dominant gravitational wave frequency associated with the instability correlates with the effective stiffness and compactness of the proto-neutron star: models with more compact/stiffer configurations emit at higher frequencies. This suggests that, in rapidly rotating core-collapse supernovae, the frequency of the low-T /|W | instability-driven gravitational wave signal may provide a diagnostic of the dense-matter equation of state, complementary to the information carried by the neutrino signal.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"63 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923307","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}

引用次数: 0

Non-variational scalar field cosmology: Exact Bianchi I solutions for near-minimal scalar fields 非变分标量场宇宙学：近极小标量场的精确Bianchi I解

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-09-10 DOI: 10.1088/1361-6382/aea5cc

Joshua Stephen Ritchie

{"title":"Non-variational scalar field cosmology: Exact Bianchi I solutions for near-minimal scalar fields","authors":"Joshua Stephen Ritchie","doi":"10.1088/1361-6382/aea5cc","DOIUrl":"https://doi.org/10.1088/1361-6382/aea5cc","url":null,"abstract":"Abstract The purpose of this work is to investigate spatially homogeneous and flat cosmological solutions of the Einstein equations coupled to a non-variational \"near-minimal\" scalar field. This coupling model represents a minimal departure from standard theory by decoupling the scalar field's self-interaction term from the derivative of its potential. By assuming a quadratic potential and a self-interaction term that is proportional to the potential, we derive four new exact Bianchi I solutions. We demonstrate that these solutions produce a diverse range of cosmological phenomena, including Big Bang, Big Crunch, and Big Rip singularities, as well as oscillatory (\"cyclic\") behaviour. For our exact solutions, these singularities occur in infinite proper time and hence are never truly reachable by an observer. To assess the stability of these cosmologies, we perform a numerical stability analysis against spatially inhomogeneous perturbations of the mean curvature. We find that the oscillatory solution is unstable to perturbations of this type, as are solutions in possession of a crushing singularity. Conversely, solutions with a Big Rip singularity (at infinity) are stable to spatially inhomogeneous perturbations of the mean curvature.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"50 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148923306","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}

引用次数: 0