Classical and Quantum Gravity最新文献_第5页

Quantum generalisation of Einstein’s equivalence principle can be verified with entangled clocks as quantum reference frames 用纠缠时钟作为量子参照系可验证爱因斯坦等效原理的量子广义化

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-22 DOI: 10.1088/1361-6382/ad6d26

Carlo Cepollaro and Flaminia Giacomini

{"title":"Quantum generalisation of Einstein’s equivalence principle can be verified with entangled clocks as quantum reference frames","authors":"Carlo Cepollaro and Flaminia Giacomini","doi":"10.1088/1361-6382/ad6d26","DOIUrl":"https://doi.org/10.1088/1361-6382/ad6d26","url":null,"abstract":"The Einstein equivalence principle (EEP) is of crucial importance to test the foundations of general relativity. When the particles involved in the test exhibit quantum properties, it is unknown whether this principle still holds. A violation of the EEP would have drastic consequences for physics. A more conservative possibility is that the EEP holds in a generalised form for delocalised quantum particles. Here we formulate such a generalised EEP by extending one of its paradigmatic tests with clocks to quantum clocks that are in a quantum superposition of positions and velocities. We show that the validity of such a generalised version of the EEP is equivalent to the possibility of transforming to the perspective of an arbitrary Quantum Reference Frame (QRF), namely a reference frame associated to the quantum state of the clock. We further show that this generalised EEP can be verified by measuring the proper time of entangled clocks in a quantum superposition of positions in the Earth gravitational field. The violation of the generalised EEP corresponds to the impossibility of defining dynamical evolution in the frame of each clock, and results in a modification to the probabilities of measurements calculated in the laboratory frame. Hence, it can be verified experimentally, for instance in an atom interferometer.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142042462","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

Modified Einstein equations from the 1-loop effective action of the IKKT model 来自 IKKT 模型一环有效作用的修正爱因斯坦方程

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-22 DOI: 10.1088/1361-6382/ad6e4b

Kaushlendra Kumar and Harold C Steinacker

引用次数: 0

Solving the area-length systems in discrete gravity using homotopy continuation 利用同调延续求解离散引力中的面积-长度系统

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-21 DOI: 10.1088/1361-6382/ad6dcc

Seth K Asante and Taylor Brysiewicz

引用次数: 0

Scalar cosmological perturbations from quantum gravitational entanglement 来自量子引力纠缠的标量宇宙学扰动

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-20 DOI: 10.1088/1361-6382/ad6f67

Alexander F Jercher, Luca Marchetti and Andreas G A Pithis

引用次数: 0

Quantum geometrodynamics revived: II. Hilbert space of positive definite metrics 量子几何力学的复兴：II.正定度量的希尔伯特空间

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-19 DOI: 10.1088/1361-6382/ad4130

Thorsten Lang and Susanne Schander

{"title":"Quantum geometrodynamics revived: II. Hilbert space of positive definite metrics","authors":"Thorsten Lang and Susanne Schander","doi":"10.1088/1361-6382/ad4130","DOIUrl":"https://doi.org/10.1088/1361-6382/ad4130","url":null,"abstract":"This paper represents the second in a series of works aimed at reinvigorating the quantum geometrodynamics program. Our approach introduces a lattice regularization of the hypersurface deformation algebra, such that each lattice site carries a set of canonical variables given by the components of the spatial metric and the corresponding conjugate momenta. In order to quantize this theory, we describe a representation of the canonical commutation relations that enforces the positivity of the operators for all choices of s. Moreover, symmetry of and is ensured. This reflects the physical requirement that the spatial metric should be a positive definite, symmetric tensor. To achieve this end, we resort to the Cholesky decomposition of the spatial metric into upper triangular matrices with positive diagonal entries. Moreover, our Hilbert space also carries a representation of the vielbein fields and naturally separates the physical and gauge degrees of freedom. Finally, we introduce a generalization of the Weyl quantization for our representation. We want to emphasize that our proposed methodology is amenable to applications in other fields of physics, particularly in scenarios where the configuration space is restricted by complicated relationships among the degrees of freedom.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007324","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 geometrodynamics revived I. Classical constraint algebra 量子几何力学的复兴 I. 经典约束代数

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-19 DOI: 10.1088/1361-6382/ad41b1

Thorsten Lang and Susanne Schander

引用次数: 0

A space-borne ultra-stable laser system with an excellent long-term frequency stability for gravitational wave detection 用于引力波探测的具有出色长期频率稳定性的空载超稳定激光系统

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-19 DOI: 10.1088/1361-6382/ad6c9d

Jialu Chang, Qiyue Wu, Zhiyuan Wang, Jingxuan Zhang, Qiang Wei, Wenhao Yuan, Deyuan Zhu, Jiarui Zhang, Xuying Li, Xinpeng Wu, Zehuang Lu and Jie Zhang

{"title":"A space-borne ultra-stable laser system with an excellent long-term frequency stability for gravitational wave detection","authors":"Jialu Chang, Qiyue Wu, Zhiyuan Wang, Jingxuan Zhang, Qiang Wei, Wenhao Yuan, Deyuan Zhu, Jiarui Zhang, Xuying Li, Xinpeng Wu, Zehuang Lu and Jie Zhang","doi":"10.1088/1361-6382/ad6c9d","DOIUrl":"https://doi.org/10.1088/1361-6382/ad6c9d","url":null,"abstract":"Ultra-stable lasers are pivotal in various scientific applications, notably in space gravitational wave detection projects. We develop a space-borne ultra-stable laser system based on a home-made non-planar ring oscillator (NPRO) laser and an ultra-stable cavity laser stabilization system. The ultra-stable cavity is a vertically mounted 8 cm long cavity, with tunable zero-crossing temperature and low vibrational sensitivity. To make a cavity with any standard grade ultra-low expansion glass (ULE) material, and tune the zero-crossing temperature to the satellite platform temperature, we design three ultra-stable cavities with different configurations to unambiguously explore their thermal properties. The measurement results meet the design goals well, and the zero-crossing temperature of the cavity can be tuned from C to 16.0 °C. We measure the temperature fluctuation noise through modulation experiment, and it agrees well with the theoretical simulations. The vibrational sensitivities in three directions are measured to be around 10−11 /g–10−10 /g. The total weight of the system is 14.0 kg, with a volume of about 18 L, and the power dissipation of the electrical system is 18.6 W. Finally, the prototype of the space-borne laser shows a frequency instability of 9.5 at 0.2 s, and the frequency noise is measured to be 3.6 Hz/Hz1/2 at 6 mHz over three months, satisfying the mission targets of all current space gravitational wave detection programs.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007328","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 note on the junction conditions in f ( Q ... 关于 f ( Q ... 中结点条件的说明

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-19 DOI: 10.1088/1361-6382/ad6be0

Stefano Vignolo, Fabrizio Esposito and Sante Carloni

引用次数: 0

Renormalization of conformal infinity as a stretched horizon 作为拉伸视界的共形无限的重正化

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-13 DOI: 10.1088/1361-6382/ad5cbb

Aldo Riello and Laurent Freidel

引用次数: 0

Four S T ... 四个 S T ...

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-08-13 DOI: 10.1088/1361-6382/ad694e

Yassine Sekhmani, Dhruba Jyoti Gogoi, Ratbay Myrzakulov, Giuseppe Gaetano Luciano and Javlon Rayimbaev

{"title":"Four S T ...","authors":"Yassine Sekhmani, Dhruba Jyoti Gogoi, Ratbay Myrzakulov, Giuseppe Gaetano Luciano and Javlon Rayimbaev","doi":"10.1088/1361-6382/ad694e","DOIUrl":"https://doi.org/10.1088/1361-6382/ad694e","url":null,"abstract":"In this work, we examine the optical behaviors and thermodynamic phase structures using shadow analysis for four black holes. The study is conducted for four cases of charge configurations on the parameter space . As a matter of fact, both the electric charge as a parameter and the parameter space affect the geometry of the black hole shadow, particularly the size of the shadow. We also introduce a constraint on the charge of the black hole from the observational results of the M87 and Sgr A shadow. Furthermore, we show that the electric charge and the parameter space have a non-trivial impact on the variation of the energy emission rate. Interestingly enough, we find novel scenarios in which the evaporation is slower, which causes the lifetime of the black holes to be considerably elongated. On the other side, the phase structure of four black holes is explored for two cases of electric charge configuration. The findings show a perfect correlation between the shadow and event horizon radii. This correlation is, in fact, helpful in discovering the phase transition in terms of the shadow radius. In addition, the microstructure is being analyzed in terms of shadow analysis, providing similar behavior to the ordinary situation of the Ruppeiner formalism.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141980977","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