Classical and Quantum Gravity最新文献_第10页

Globally hyperbolic evaporating black hole and the information loss issue 全球双曲型蒸发黑洞与信息丢失问题

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-27 DOI: 10.1088/1361-6382/adb534

Juan V O Pêgas, André G S Landulfo, George E A Matsas and Daniel A T Vanzella

引用次数: 0

Geometry of Carrollian stretched horizons 卡罗里安几何学延展了视界

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-27 DOI: 10.1088/1361-6382/adaf6e

Laurent Freidel and Puttarak Jai-akson

{"title":"Geometry of Carrollian stretched horizons","authors":"Laurent Freidel and Puttarak Jai-akson","doi":"10.1088/1361-6382/adaf6e","DOIUrl":"https://doi.org/10.1088/1361-6382/adaf6e","url":null,"abstract":"In this paper, we present a comprehensive toolbox for studying Carrollian stretched horizons, encompassing their geometry, dynamics, symplectic geometry, symmetries, and corresponding Noether charges. We introduce a precise definition of ruled stretched Carrollian structures (sCarrollian structures) on any surface, generalizing the conventional Carrollian structures of null surfaces, along with the notions of sCarrollian connection and sCarrollian stress tensor. Our approach unifies the sCarrollian (intrinsic) and stretched horizon (embedding) perspectives, providing a universal framework for any causal surface, whether timelike or null. We express the Einstein equations in sCarrollian variables and discuss the phase space symplectic structure of the sCarrollian geometry. Through Noether’s theorem, we derive the Einstein equation and canonical charge and compute the evolution of the canonical charge along the transverse (radial) direction. The latter can be interpreted as a spin-2 symmetry charge. Our framework establishes a novel link between gravity on stretched horizons and Carrollian fluid dynamics and unifies various causal surfaces studied in the literature, including non-expanding and isolated horizons. We expect this work to provide insights into the hydrodynamical description of black holes and the quantization of null surfaces.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"15 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143506787","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

Gravitation as a statistical theory on the light cone 引力作为光锥的统计理论

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-26 DOI: 10.1088/1361-6382/ada967

José M Isidro, Claudio F Paganini and Alessandro Pesci

{"title":"Gravitation as a statistical theory on the light cone","authors":"José M Isidro, Claudio F Paganini and Alessandro Pesci","doi":"10.1088/1361-6382/ada967","DOIUrl":"https://doi.org/10.1088/1361-6382/ada967","url":null,"abstract":"In this paper, we will explore Padmanabhan’s mesoscopic, statistical approach to gravity (Padmanathan 2017 J. Phys.: Conf. Ser.880 012008) with a twist. The general picture of his approach is that spacetime is made of large numbers of localized quantum degrees of freedom. Padmanabhan assumed that the degrees of freedom of a given quantum state of geometry contribute, after averaging over fluctuations, a vector degree of freedom for spacetime at a point. For null vectors, this can be regarded as corresponding to one single vector, i.e. a pure state, for the statistical ensemble on the light cone at every point. In the present paper, we consider instead the case where the states of the gravitational degrees of freedom are spread out and overlap, with only probabilistic information on which of them determines the actual spacetime at a point. In the continuum limit, this corresponds to a mixed state for the statistical ensemble on the light cone at every point. This change in assumptions leads to some interesting observations. When we define a statistical ensemble on the light cone, its variance ‘knows’ about the interior of the light cone. As an intriguing consequence, we find that the cosmological constant can be related to the variance over the light cone. With a mixed state, we can no longer derive the gravitational field equations from an entropy functional. Here, instead, we show that a naive implementation of the measure of a mixed state on the light cone in the variation principle leads to modified measure theories as the grand canonical ensemble and allows one to reframe unimodular gravity as the canonical ensemble of a statistical theory on the light cone.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"14 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495384","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

Analytic weak-signal approximation of the Bayes factor for continuous gravitational waves 连续引力波贝叶斯因子的解析弱信号近似

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-26 DOI: 10.1088/1361-6382/adb097

Reinhard Prix

{"title":"Analytic weak-signal approximation of the Bayes factor for continuous gravitational waves","authors":"Reinhard Prix","doi":"10.1088/1361-6382/adb097","DOIUrl":"https://doi.org/10.1088/1361-6382/adb097","url":null,"abstract":"We generalize the targeted -statistic for continuous gravitational waves by modeling the h0-prior as a half-Gaussian distribution with scale parameter H. This approach retains analytic tractability for two of the four amplitude marginalization integrals and recovers the standard -statistic in the strong-signal limit ( ). By Taylor-expanding the weak-signal regime ( ), the new prior enables fully analytic amplitude marginalization, resulting in a simple, explicit statistic that is as computationally efficient as the maximum-likelihood -statistic, but significantly more robust. Numerical tests show that for day-long coherent searches, the weak-signal Bayes factor achieves sensitivities comparable to the -statistic, though marginally lower than the standard -statistic (and the Bero-Whelan approximation). In semi-coherent searches over short (compared to a day) segments, this approximation matches or outperforms the weighted dominant-response -statistic and returns to the sensitivity of the (weighted) -statistic for longer segments. Overall the new Bayes-factor approximation demonstrates state-of-the-art or improved sensitivity across a wide range of segment lengths we tested (from 900 s to 10 days).","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"26 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495387","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

Quantum curved tetrahedron, quantum group intertwiner space, and coherent states 量子弯曲四面体、量子群缠结空间和相干态

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-26 DOI: 10.1088/1361-6382/adb533

Chen-Hung Hsiao and Qiaoyin Pan

引用次数: 0

Quantum BPS cosmology 量子BPS宇宙学

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-26 DOI: 10.1088/1361-6382/adb6ed

Nahomi Kan, Kiyoshi Shiraishi, Maki Takeuchi and Mai Yashiki

引用次数: 0

Heat capacities and thermodynamic geometry in deformed Jackiw–Teitelboim gravity 变形Jackiw-Teitelboim重力的热容和热力学几何

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-25 DOI: 10.1088/1361-6382/adb535

H Babaei-Aghbolagh, Mirmani Mirjalali, Davood Mahdavian Yekta, Komeil Babaei Velni and Hosein Mohammadzadeh

{"title":"Heat capacities and thermodynamic geometry in deformed Jackiw–Teitelboim gravity","authors":"H Babaei-Aghbolagh, Mirmani Mirjalali, Davood Mahdavian Yekta, Komeil Babaei Velni and Hosein Mohammadzadeh","doi":"10.1088/1361-6382/adb535","DOIUrl":"https://doi.org/10.1088/1361-6382/adb535","url":null,"abstract":"In this paper, we will study some thermodynamic features and phase structure of charged AdS black holes in deformed Jackiw–Teitelboim (dJT) gravity. We find the values of temperature, entropy and electric charge at the critical inflection points of the corresponding solutions. In addition, we compute the heat capacity as thermal stability parameter along with the expansion coefficient and isothermal compressibility as thermodynamic response functions in dJT model. It is shown that they are divergent at the critical points of the isocharge curves and satisfy the Ehrenfest’s equations which discloses this fact that the phase transition at the critical points is of second order. In the context of thermodynamic geometry, we also compute the state scalar curvature, R, of these black holes following three practical methods; Weinhold, Ruppeiner and New thermodynamic geometry. This provides more insights into the behavior and significance of the scalar curvature near the critical points of charged AdS black holes in dJT theory, analogous to that for conventional critical phenomena.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"65 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143485717","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

Odd parity gravitational waves in modified Bianchi I cosmology 修正Bianchi I宇宙论中的奇宇称引力波

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-25 DOI: 10.1088/1361-6382/adb532

Arsal Kamal, Rubab Manzoor, Oktay Aydogdu, Mustafa Salti and Aisha Siddiqa

引用次数: 0

Gravitational wave signal prediction technique based on advanced seasonal-trend decomposition using Loess 基于黄土超前季节趋势分解的引力波信号预测技术

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-25 DOI: 10.1088/1361-6382/adb2d5

Dongbao Jia, Rui Ma, Weixiang Xu, Shiwei Zhao, Wenjun Ruan and Zhongxun Xu

{"title":"Gravitational wave signal prediction technique based on advanced seasonal-trend decomposition using Loess","authors":"Dongbao Jia, Rui Ma, Weixiang Xu, Shiwei Zhao, Wenjun Ruan and Zhongxun Xu","doi":"10.1088/1361-6382/adb2d5","DOIUrl":"https://doi.org/10.1088/1361-6382/adb2d5","url":null,"abstract":"Gravitational wave (GW) analysis is attracting widespread attention as an emerging research field. As the presence of substantial noise in GW signals, and the characteristics of inspiral and merger stage are different, coupled with the sidelobe effect caused by window length, traditional time–frequency analysis methods face significant challenges in accurately analyzing the frequency variations of GW signals. This poses a major limitation in the precise analysis stage following GW detection. Therefore, we proposed a novel method of seasonal-trend decomposition using Loess with multilayer perceptron (STLMLP), for predicting and validating the accuracy and effectiveness of GW frequency variations. Experiment results on three noiseless GW templates demonstrate that STLMLP exhibits the adaptability and highest prediction accuracy for the dynamic frequency variations of GW signals compared to five state-of-the-art machine learning and deep learning methods. Furthermore, experiments conducted on three noisy actual GW data compared with the state-of-the-art method of Fourier-based synchrosqueezing transform in the signal processing domain confirm that STLMLP maintains lower error in predicting frequency change over the whole duration of the actual noisy GW signals.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"26 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143485719","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

Evidence for Planck luminosity bound in quantum gravity 量子引力中普朗克光度约束的证据

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-21 DOI: 10.1088/1361-6382/adb536

Wolfgang Wieland

引用次数: 0