Classical and Quantum Gravity最新文献_第9页

The variance of the CMB temperature gradient: a dependence on the spatial orientation and anisotropy of a multiply connected Universe 微波背景温度梯度的变化：依赖于多连通宇宙的空间取向和各向异性

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-27 DOI: 10.1088/1361-6382/ae9fac

Ralf Aurich,Martin Jacques France,Frank Steiner

{"title":"The variance of the CMB temperature gradient: a dependence on the spatial orientation and anisotropy of a multiply connected Universe","authors":"Ralf Aurich,Martin Jacques France,Frank Steiner","doi":"10.1088/1361-6382/ae9fac","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9fac","url":null,"abstract":"Abstract In the present work we develop a model–independent method to reveal the underlying patterns of anisotropy and geometry in CMB temperature maps. This method, based on the ρ−statistics and a process of mask–sweeping, unveils faint but persistent geometrical and periodic structures characterising the anisotropy of the CMB in a universe with 3−torus topology. We assess that the patterns detected over large ensembles of toroidal maps match geometrically to the layouts of expected circles-in-the-sky. The mask–sweeping method explores the whole CMB over 768 mask orientations. Thus we are able to re-verify the linear relation between L the size of the cubic torus and ρ the standard deviation of the normalised variance of the CMB temperature gradient. This confers a finite size s≃3 Hubble lengths to our Universe with toroidal topology. Furthermore, it is shown that the violation of statistical isotropy is so faint that this has almost no influence on the linear relation between ρ and L. A topology like the cubic toroidal one imposes to our Universe periodic conditions (that can be seen as periodic boundary conditions) which constrain the global degree of inhomogeneity and a zero average curvature. We demonstrate here that ρ is not only a statistical signature of the spatial finiteness and size of our Universe (may its topology be simply or multiply connected) but also outlines the patterns of anisotropy of the CMB with the help of the mask–sweeping process.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"15 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893783","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

Cryogenic sub-Hz cROss torsion bar detector with quantum NOn-demolition speed meter (CHRONOS) for gravitational-wave detection 用于引力波探测的低温亚赫兹交叉扭棒探测器与量子非拆卸速度计（CHRONOS）

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-27 DOI: 10.1088/1361-6382/ae91c4

Yuki Inoue,Daiki Tanabe,M Afif Ismail,Vivek Kumar,Mario Juvenal S Onglao III,Ta-Chun Yu

{"title":"Cryogenic sub-Hz cROss torsion bar detector with quantum NOn-demolition speed meter (CHRONOS) for gravitational-wave detection","authors":"Yuki Inoue,Daiki Tanabe,M Afif Ismail,Vivek Kumar,Mario Juvenal S Onglao III,Ta-Chun Yu","doi":"10.1088/1361-6382/ae91c4","DOIUrl":"https://doi.org/10.1088/1361-6382/ae91c4","url":null,"abstract":"Abstract We present the optical design and sensitivity modeling of the Cryogenic sub-Hz cROss torsion-bar detector with quantum NOn-demolition Speed meter (CHRONOS), a triangular Sagnac speed-meter interferometer incorporating power- and signal-recycling techniques. Using ABCD-matrix analysis and Finesse3 simulations, we show that stable eigenmodes are obtained with optimized mirror curvatures and focal placements, achieving mode-matching efficiencies above 99.5%. The configuration reaches a quantum-noise-limited strain sensitivity of h ≃ 1 × 10 − 18 Hz − 1 / 2 at 2 Hz, with a ring-cavity finesse F ≃ 3.1 × 10 4 and a round-trip Gouy phase ψ ≈ 153 ∘ . The power-recycling cavity detuning ( ϕ p = 5 ∘ ) dominates the low-frequency quantum noise, while the signal-recycling cavity detuning ( ϕ s = 0 ∘ ) mainly introduces a uniform quadrature rotation. The optimal homodyne angle ( ζ ≃ 46 ∘ ) balances shot noise and radiation-pressure effects to give the best sensitivity near 1 Hz. Assuming an end-mirror reflectivity R ETM = 99.9999 % under cryogenic operation at 8 K, CHRONOS can achieve quantum-noise-limited performance on a laboratory scale and serve as a testbed for future long-baseline cryogenic interferometers probing sub-hertz gravitational waves. The projected science reach includes the detection of intermediate-mass black-hole binaries with total masses of 10 2 – 10 5 M ⊙ , reaching a maximum detection distance of ∼ 271 Mpc for binaries with total masses around 9 × 10 3 M ⊙ (SNR = 1). The detector also achieves a best power-integrated sensitivity to stochastic gravitational-wave backgrounds of Ω GW ≃ 4.7 × 10 − 4 at 2.15 Hz after 10 years of observation, probes Yukawa-type deviations from Newtonian gravity down to | α | ∼ 2 × 10 − 5 , and can detect prompt gravity-gradient signals from nearby M5.2 earthquakes out to distances of approximately 90 km .","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"15 1","pages":"165022"},"PeriodicalIF":3.5,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893778","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

A quarkyonic matter model: rapid stiffening driven by quark saturation 夸克物质模型：夸克饱和驱动下的快速硬化

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-27 DOI: 10.1088/1361-6382/ae94d5

Toru Kojo

{"title":"A quarkyonic matter model: rapid stiffening driven by quark saturation","authors":"Toru Kojo","doi":"10.1088/1361-6382/ae94d5","DOIUrl":"https://doi.org/10.1088/1361-6382/ae94d5","url":null,"abstract":"Abstract Quarkyonic matter is a state of matter in dense QCD whose bulk thermodynamics is dominated by quarks, while low-energy excitations remain confined. This picture leads to a crossover description from baryonic matter to quark matter, which is triggered by the saturation of quark states in dense matter ( quark saturation ). The crossover driven by the quark saturation accompanies rapid growth in pressure but moderate increase in energy density, resulting in a characteristic peak in the sound speed. Such a rapid stiffening is consistent with constraints inferred from neutron star observations. The quark saturation can occur at a few times nuclear saturation density, which is smaller than the density at which the baryon cores of ∼ 0.5 – 0.8 fm spatially overlap. In this contribution we discuss an ideal model of quarkyonic matter, the IdylliQ model, and we explicitly describe how the baryon and quark occupation probabilities are related, and explain how stiffening of matter occurs. The model is further applied to charge neutral matter including hyperons, and it is shown that the statistical constraints at quark level induce effective repulsion among different baryon species, mitigating the hyperon softening problem in neutron star physics.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"29 1","pages":"165021"},"PeriodicalIF":3.5,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893780","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

Universality classes of interacting dark energy from spontaneous symmetry breaking 自发对称破缺中相互作用暗能量的普适性类

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-27 DOI: 10.1088/1361-6382/ae98d9

Pradosh Keshav MV,N S Kavya,Kenath Arun

{"title":"Universality classes of interacting dark energy from spontaneous symmetry breaking","authors":"Pradosh Keshav MV,N S Kavya,Kenath Arun","doi":"10.1088/1361-6382/ae98d9","DOIUrl":"https://doi.org/10.1088/1361-6382/ae98d9","url":null,"abstract":"Abstract Phenomenological models of interacting dark energy (IDE) often treat the late-time activation history of the dark sector coupling as an independent function. We show that in conformally coupled scalar–tensor theories, this freedom is constrained by the local restoring structure of the symmetry-breaking potential. Within the adiabatic tracking regime, the coupling evolution satisfies n = 3 / p , where p is the restoring order near the broken minimum thereby organizing distinct symmetry-breaking potentials such as quartic, Coleman–Weinberg, and axion-like forms into a common asymptotic dynamical class ( p = 1 , n = 3 ). We test this framework using Planck 2018 cosmic microwave background lensing, redshift-space distortions, and Pantheon+SH0ES supernova data. Current observations provide only limited discrimination between the predicted activation classes and yield no statistically significant evidence for a nonzero interaction with | β 0 | ≲ 0.26 at 95 % credibility. At the same time, the rigid asymptotic implementation ( n = 3 ) is strongly disfavored by the combined geometric and growth constraints indicating that the observable coupling history cannot be identified directly with its asymptotic attractor form. In the heavy-scalar adiabatic regime, the modifications to the growth rate f ( z ) and growth factor D ( z ) are of opposite sign throughout 0 ⩽ z ≤ 2 , suppressing the net deviation in f σ 8 ( z ) to Δ f σ 8 / f σ 8 ≲ 0.3 % across the posterior. Standard growth-rate measurements therefore have limited sensitivity to this class of models, shifting the observational focus toward probes that constrain f ( z ) and D ( z ) independently. Taken together, these results establish a dynamical classification of late-time IDE activation histories and clarify how finite-redshift observables are related to the asymptotic attractor structure and the local restoring properties of the underlying scalar potential.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"10 1","pages":"165019"},"PeriodicalIF":3.5,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893779","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

Matrix model for quantized dilaton black holes with geometric deformation 几何变形的量子化膨胀黑洞的矩阵模型

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-27 DOI: 10.1088/1361-6382/ae98d7

Reza Baghbani

{"title":"Matrix model for quantized dilaton black holes with geometric deformation","authors":"Reza Baghbani","doi":"10.1088/1361-6382/ae98d7","DOIUrl":"https://doi.org/10.1088/1361-6382/ae98d7","url":null,"abstract":"Abstract We construct a matrix model for the quantization of a four-dimensional dilaton black hole featuring a geometrically deformed angular sector r 2 R ( r ) 2 , with R ( r ) = ( r / r 0 ) H . By promoting spatial coordinates to N × N Hermitian matrices and deforming the kinetic and commutator terms via the spectral operator R ( R ) , we show that the eigenvalue distribution encodes a quantum geometry that reproduces the classical black hole background in the large- N limit. The thermodynamic entropy scales as S ∼ α ( H ) N 2 log ⁡ N + β ( H ) N 2 , matching the generalized Bekenstein–Hawking law when G N ∝ 1 / N 2 and r + ∝ N 1 / ( H + 1 ) . We demonstrate that H acts as a physical control parameter driving genuine quantum phase transitions at H c = − 1 / 2 and H c = − 3 / 4 , accompanied by dimensional reduction and non-analytic behavior in the order parameter. The entanglement entropy between matrix subsystems obeys a deformed area law, confirming holographic scaling. Furthermore, we explicitly reconstruct the emergent spacetime metric and verify that it satisfies the deformed Einstein–dilaton field equations. Finally, we prove that in the limit H → 0 , the model reduces exactly to the BFSS matrix theory, whose semi-classical limit yields the Reissner–Nordström–AdS black hole, establishing the framework as a consistent, non-perturbative quantization of deformed gravity.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"493 1","pages":"165020"},"PeriodicalIF":3.5,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893781","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

On the Finsler variational nature of autoparallels in metric-affine geometry 度量仿射几何中自平行线的Finsler变分性质

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-26 DOI: 10.1088/1361-6382/ae9f11

Lehel Csillag,Nicoleta Voicu,Salah Gomaa Elgendi,Christian Pfeifer

引用次数: 0

Effective Quantum Gravitational Collapse in Metric Variables: The μ-bar Scheme 度量变量中的有效量子引力坍缩：μ棒格式

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-26 DOI: 10.1088/1361-6382/ae9f0f

Lorenzo Boldorini,Giovanni Montani

引用次数: 0

Core-Collapse Supernova Simulations and Collective Neutrino Flavor Conversions: Current Status and Prospects 核心坍缩超新星模拟与集体中微子风味转换：现状与展望

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-26 DOI: 10.1088/1361-6382/ae9f10

Jiabao Liu,Akira Harada,Hiroki Nagakura

引用次数: 0

Large black holes at a finite distance: Quasi-local restricted phase space formalism 有限距离的大黑洞：准局域限制相空间形式

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-26 DOI: 10.1088/1361-6382/ae9eaa

Bai-Hao Huang,Liu Zhao

{"title":"Large black holes at a finite distance: Quasi-local restricted phase space formalism","authors":"Bai-Hao Huang,Liu Zhao","doi":"10.1088/1361-6382/ae9eaa","DOIUrl":"https://doi.org/10.1088/1361-6382/ae9eaa","url":null,"abstract":"Abstract We extend the restricted phase space formalism for spherically symmetric black hole solutions of Einstein-Maxwell theory to the quasi-local regime, with the static observers located at a finite radial distance. The first law and Euler relation for the RN and RN-AdS black holes are proved to hold, but only with the inclusion of an extra pair of thermodynamic variables, i.e. the pressure P and the area A of the codimension-2 hypersurface on which the observers reside. For the RN black holes, the quasi-local behavior is analyzed in detail. It turns out that the RN black holes in the quasi-local description behaves significantly different from itself in the asymptotic description, but is extremely similar to the RN-AdS black holes in the asymptotic description, e.g. allowing for isocharge temperature-entropy phase transitions and lack of isovoltage temperature-entropy phase transitions. In the neutral limit, the Hawking-Page-like transitions appear in the quasi-local description which is absent in the asymptotic description. The quasi-local behavior of RN-AdS black holes is also briefly discussed, which is qualitatively identical to the asymptotic description with only quantitative differences.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"15 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893785","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

GGI lectures on boundary and asymptotic symmetries 关于边界和渐近对称的GGI讲座

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2026-08-25 DOI: 10.1088/1361-6382/ae8aa9

Simone Speziale

引用次数: 0