Classical and Quantum Gravity最新文献_第9页

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

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Smearing out contact terms in ghost-free infinite derivative quantum gravity 无鬼无限导数量子引力中接触项的抹去

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/adb08c

Ulrich K Beckering Vinckers, Álvaro de la Cruz-Dombriz and Anupam Mazumdar

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Theoretical analysis and simulation verification for measuring the geometric distances between the silicon spheres with the laser interferometer in G measurement 用激光干涉仪测量G测量中硅球间几何距离的理论分析与仿真验证

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-19 DOI: 10.1088/1361-6382/adb2d6

Tong Huang, Rui-Qi Liu, Rui-Jie Li, Ling-Ling Yang, Yan-Jie Zhang, Qiang-Bing Mao and Qing Li

{"title":"Theoretical analysis and simulation verification for measuring the geometric distances between the silicon spheres with the laser interferometer in G measurement","authors":"Tong Huang, Rui-Qi Liu, Rui-Jie Li, Ling-Ling Yang, Yan-Jie Zhang, Qiang-Bing Mao and Qing Li","doi":"10.1088/1361-6382/adb2d6","DOIUrl":"https://doi.org/10.1088/1361-6382/adb2d6","url":null,"abstract":"The Newtonian gravitational constant G is one of the most fundamental constants in nature. In G measurement with the angular acceleration feedback method, the largest error comes from the distances between the geometric centers of the source masses. In the on-going experiment, the silicon spheres with a more homogeneous density are used as the source masses. Here a scheme of measuring the geometric distances between the silicon spheres with the laser interferometer is proposed. The measurement principle is analyzed, and the error sources, such as the laser, the sphere, the alignment of optical path, and the environment are evaluated. With this method, the horizontal and vertical geometric distances can be measured with uncertainties of 11 nm and 9 nm, respectively. The simulation is performed to verify the theoretical model of measuring the distance, where the maximum deviation between the simulation result and the theoretical one is only −2.7 nm. When the sphericities of the four silicon spheres are at the level of 0.1 µm, the uncertainty of each distance after considering the sphericity is about 0.1 µm, corresponds to a combined uncertainty of 0.6 ppm for G measurement with the angular acceleration feedback method. This provides an effective method to reduce the measurement uncertainty of geometric distance between the silicon spheres, and makes it possible to measure G with a higher precision.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"1 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443250","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

Revisiting the dynamics of a charged spinning body in curved spacetime 重新审视弯曲时空中带电自旋体的动力学

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-18 DOI: 10.1088/1361-6382/adb2d4

K Andrzejewski

引用次数: 0

For a flat Universe, C P /... 对于平坦的宇宙，C P /…

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-18 DOI: 10.1088/1361-6382/adb2d3

Somnath Saha, Subhajit Saha and Nilanjana Mahata

{"title":"For a flat Universe, C P /...","authors":"Somnath Saha, Subhajit Saha and Nilanjana Mahata","doi":"10.1088/1361-6382/adb2d3","DOIUrl":"https://doi.org/10.1088/1361-6382/adb2d3","url":null,"abstract":"This paper deals with gravitational thermodynamics on the dynamical apparent horizon of an Friedmann–Lemaitre–Robertson–Walker (FLRW) Universe with dissipation. The dissipation is assumed to arise due to adiabatic gravitational particle creation. For the thermodynamic study, we consider the Bekenstein–Hawking formalism and also assume a nonzero curvature κ for a general study. In particular, we study the unified first law, the generalized second law, and thermodynamic stability in our model. The specific heat capacities are taken into account for the study of thermodynamic stability. Our study reveals a nice result! The ratio of the specific heat capacity at constant pressure and that at constant volume in a flat FLRW Universe with dissipation is nothing but the negative of the deceleration parameter. In classical thermodynamics, this ratio is known as the isentropic expansion factor or (for ideal gases) the adiabatic index. A more interesting fact that has come to light is that this relation is independent of the cosmological model used. So, this is actually a generic result in big bang cosmology. We discuss the implications of this result on the evolution of the Universe. Finally, we determine the constraints on the effective equation of state and the particle creation rate which guarantees thermodynamic stability in our model.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"64 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435046","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

Clock synchronization and light-travel-time estimation for space-based gravitational-wave detectors 天基引力波探测器的时钟同步与光行时估计

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-17 DOI: 10.1088/1361-6382/ada2d3

Jan Niklas Reinhardt, Olaf Hartwig and Gerhard Heinzel

{"title":"Clock synchronization and light-travel-time estimation for space-based gravitational-wave detectors","authors":"Jan Niklas Reinhardt, Olaf Hartwig and Gerhard Heinzel","doi":"10.1088/1361-6382/ada2d3","DOIUrl":"https://doi.org/10.1088/1361-6382/ada2d3","url":null,"abstract":"Space-based gravitational-wave detectors, such as the Laser Interferometer Space Antenna (LISA), record interferometric measurements on widely separated satellites. Their clocks are not synced actively. Instead, clock synchronization is performed in on-ground data processing. It relies on measurements of the so-called pseudoranges, which entangle the interspacecraft light travel times (LTTs) with the clock desynchronizations between emitting and receiving spacecraft. For interspacecraft clock synchronization, we need to isolate the differential clock desynchronizations, i.e. disentangle the pseudoranges. This further yields estimates for the interspacecraft LTTs, which are required as delays for the laser frequency noise suppression via time-delay interferometry (TDI). Previous studies on pseudorange disentanglement apply various simplifications in the pseudorange modeling and the data simulation. In contrast, this article derives an accurate pseudorange model in the barycentric celestial reference system, complemented by realistic state-of-the-art LISA data simulations. Concerning pseudorange disentanglement, this leads to an a priori under-determined system. We demonstrate how on-ground orbit determinations, as well as onboard transmission and on-ground reception time tags of the telemetry data, can be used to resolve this degeneracy. We introduce an algorithm for pseudorange disentanglement based on a nonstandard Kalman filter specially designed for clock synchronization in systems where pseudorange measurements are conducted in different time frames. This algorithm achieves interspacecraft clock synchronization and LTT estimation with submeter accuracy, thus fulfilling the requirements of TDI.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"21 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143426973","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

Probing the axion–photon coupling with space-based gravitational wave detectors 利用天基引力波探测器探测轴-光子耦合

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-17 DOI: 10.1088/1361-6382/adb23c

Jordan Gué, Aurélien Hees and Peter Wolf

引用次数: 0

Advanced charge control dynamics simulation for the LISA gravitational reference sensor LISA重力参考传感器的先进电荷控制动力学仿真

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-17 DOI: 10.1088/1361-6382/adaf00

Samantha Parry Kenyon, Stephen Apple, John Siu, Peter J Wass and John W Conklin

{"title":"Advanced charge control dynamics simulation for the LISA gravitational reference sensor","authors":"Samantha Parry Kenyon, Stephen Apple, John Siu, Peter J Wass and John W Conklin","doi":"10.1088/1361-6382/adaf00","DOIUrl":"https://doi.org/10.1088/1361-6382/adaf00","url":null,"abstract":"A gravitational wave detector in space, the Laser Interferometer Space Antenna (LISA) will be able to detect gravitational waves in the frequency range of 0.1 mHz–1 Hz, adding to humanity’s knowledge of the dark cosmos. The LISA gravitational reference sensor contains a test mass (TM) and is used to determine the local inertial reference frame and as endpoints for the interferometry. The TM is surrounded by an electrode housing to detect changes in TM position and orientation, which is fed back to the spacecraft thrusters for drag-free control. As seen on LISA Pathfinder, the TM builds up charge over time from the space environment and needs to be discharged in order to keep the resulting force noise as low as possible. The operation of intelligently discharging the TM is known as charge control, and is one area of improvement to be explored for LISA. To explore new methods of TM discharge, UV LEDs will be pulsed synchronized with an existing 100 kHz high frequency electric field to facilitate photoelectron current direction and to achieve lower UV light powers by duty cycling. This paper addresses new pulsed methods for the LISA Charge Management System, which require in-depth modeling, analysis, and testing because space environment validation will not be possible prior to LISA launch. Therefore, it is necessary to model the dynamics of charge movement to determine the force noise contribution of pulsed continuous charge control. The charge dynamics model is described, and simulation results featured for charge control efficacy in a deep space radiation environment. Experimental testing of the simulation results could be done in the University of Florida Torsion Pendulum, a key technology to testing GRS performance in a space-like environment.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"49 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427130","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

Spikes and spines in 3D Lorentzian simplicial quantum gravity 三维洛伦兹简单量子引力中的尖刺和棘

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-17 DOI: 10.1088/1361-6382/adaf02

Johanna Borissova, Bianca Dittrich, Dongxue Qu and Marc Schiffer

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Detecting kHz gravitons from a neutron star merger with a multi-mode resonant mass detector 用多模共振质量探测器探测中子星并合的千赫重子

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-02-14 DOI: 10.1088/1361-6382/adae4a

Germain Tobar, Igor Pikovski, Michael E Tobar

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