Classical and Quantum Gravity最新文献_第10页

Effects of quantum corrections to Lorentzian vacuum transitions in the presence of gravity 重力存在下量子修正对洛伦兹真空跃迁的影响

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-30 DOI: 10.1088/1361-6382/ad9fcc

H García-Compeán, J Hernández-Aguilar, D Mata-Pacheco and C Ramírez

{"title":"Effects of quantum corrections to Lorentzian vacuum transitions in the presence of gravity","authors":"H García-Compeán, J Hernández-Aguilar, D Mata-Pacheco and C Ramírez","doi":"10.1088/1361-6382/ad9fcc","DOIUrl":"https://doi.org/10.1088/1361-6382/ad9fcc","url":null,"abstract":"We present a study of the vacuum transition probabilities taking into account quantum corrections. We first introduce a general method that expands previous works employing the Lorentzian formalism of the Wheeler–De Witt equation by considering higher order terms in the semiclassical expansion. The method presented is applicable in principle to any model in the minisuperspace and up to any desired order in the quantum correction terms. Then, we apply this method to obtain analytical solutions for the probabilities up to second quantum corrections for homogeneous isotropic and anisotropic universes. We use the Friedmann–Lemaitre–Robertson–Walker metric with positive and zero curvature for the isotropic case and the Bianchi III and Kantowski–Sachs metrics for the anisotropic case. Interpreting the results as distribution probabilities of creating universes by vacuum decay with a given size, we found that the general behaviour is that considering up to the second quantum correction leads to an avoidance of the initial singularity. However, we show that this result can only be achieved for the isotropic Universe. Furthermore, we also study the effect of anisotropy on the transition probabilities.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"15 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901835","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

Observational constraints on generic models of non-minimal curvature-matter coupling 非极小曲率-物质耦合一般模型的观测约束

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-30 DOI: 10.1088/1361-6382/ad9f18

Anirban Chatterjee, Akshay Panda and Abhijit Bandyopadhyay

引用次数: 0

A new study of the Unruh effect 一项关于昂鲁效应的新研究

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-27 DOI: 10.1088/1361-6382/ad9c12

Robert Dickinson, Jeff Forshaw, Ross Jenkinson and Peter Millington

引用次数: 0

Path integral derivation of the thermofield double state in causal diamonds 因果金刚石热场双态的路径积分推导

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-27 DOI: 10.1088/1361-6382/ad9e65

Abhijit Chakraborty, Carlos R Ordóñez and Gustavo Valdivia-Mera

{"title":"Path integral derivation of the thermofield double state in causal diamonds","authors":"Abhijit Chakraborty, Carlos R Ordóñez and Gustavo Valdivia-Mera","doi":"10.1088/1361-6382/ad9e65","DOIUrl":"https://doi.org/10.1088/1361-6382/ad9e65","url":null,"abstract":"In this article, we adopt the framework developed by Laflamme (1989 Physica A 158 58–63) to analyze the path integral of a massless—conformally invariant—scalar field defined on a causal diamond (CD) of size 2α in 1+1 dimensions. By examining the Euclidean geometry of the CD, we establish that its structure is conformally related to the cylinder , where the Euclidean time coordinate τ has a periodicity of β. This property, along with the conformal symmetry of the fields, allows us to identify the connection between the thermofield double (TFD) state of CDs and the Euclidean path integral defined on the two disconnected manifolds of the cylinder. Furthermore, we demonstrate that the temperature of the TFD state, derived from the conditions in the Euclidean geometry and analytically calculated, coincides with the temperature of the CD known in the literature. This derivation highlights the universality of the connection between the Euclidean path integral formalism and the TFD state of the CD, as well as it further establishes CDs as a model that exhibits all desired properties of a system exhibiting the Unruh effect.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"72 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142888060","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

AsterX: a new open-source GPU-accelerated GRMHD code for dynamical spacetimes AsterX：一个新的开源gpu加速GRMHD动态时空代码

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-27 DOI: 10.1088/1361-6382/ad9c11

Jay V Kalinani, Liwei Ji, Lorenzo Ennoggi, Federico G Lopez Armengol, Lucas Timotheo Sanches, Bing-Jyun Tsao, Steven R Brandt, Manuela Campanelli, Riccardo Ciolfi, Bruno Giacomazzo, Roland Haas, Erik Schnetter and Yosef Zlochower

{"title":"AsterX: a new open-source GPU-accelerated GRMHD code for dynamical spacetimes","authors":"Jay V Kalinani, Liwei Ji, Lorenzo Ennoggi, Federico G Lopez Armengol, Lucas Timotheo Sanches, Bing-Jyun Tsao, Steven R Brandt, Manuela Campanelli, Riccardo Ciolfi, Bruno Giacomazzo, Roland Haas, Erik Schnetter and Yosef Zlochower","doi":"10.1088/1361-6382/ad9c11","DOIUrl":"https://doi.org/10.1088/1361-6382/ad9c11","url":null,"abstract":"We present AsterX, a novel open-source, modular, GPU-accelerated, fully general relativistic magnetohydrodynamic (GRMHD) code designed for dynamic spacetimes in 3D Cartesian coordinates, and tailored for exascale computing. We utilize block-structured adaptive mesh refinement (AMR) through CarpetX, the new driver for the Einstein Toolkit, which is built on AMReX, a software framework for massively parallel applications. AsterX employs the Valencia formulation for GRMHD, coupled with the ‘Z4c’ formalism for spacetime evolution, while incorporating high resolution shock capturing schemes to accurately handle the hydrodynamics. AsterX has undergone rigorous testing in both static and dynamic spacetime, demonstrating remarkable accuracy and agreement with other codes in literature. Using subcycling in time, we find an overall performance gain of factor 2.5–4.5. Benchmarking the code through scaling tests on OLCF’s Frontier supercomputer, we demonstrate a weak scaling efficiency of about 67%–77% on 4096 nodes compared to an 8-node performance.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"129 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142887981","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

Sensitivity functions of space-borne gravitational wave detectors under the metric gravity theory 公制重力理论下星载引力波探测器的灵敏度函数

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-27 DOI: 10.1088/1361-6382/ad9ce0

Jing Zhou, Pan-Pan Wang and Cheng-Gang Shao

{"title":"Sensitivity functions of space-borne gravitational wave detectors under the metric gravity theory","authors":"Jing Zhou, Pan-Pan Wang and Cheng-Gang Shao","doi":"10.1088/1361-6382/ad9ce0","DOIUrl":"https://doi.org/10.1088/1361-6382/ad9ce0","url":null,"abstract":"Gravitational waves (GWs) have six possible polarization modes, and whose successful detection can effectively test the gravitational properties under the strong field theory and help distinguish between different theories of gravity. Space-based GW detectors can respond differently to different polarization modes and can be used to measure the polarization states of GWs. However, during the detection process, multiple noises can swamp the faint GW signals, thus, it is essential to develop highly sophisticated experimental techniques and data processing methods to suppress the noises. For the most dominant laser frequency noise, time-delay interferometry technique is employed to construct a virtual equal-arm interferometer by performing appropriate time-delay and linear combination of data streams. This ensures the laser frequency noise is suppressed below the noise floor composed of test-mass noise and shot noise. To present the responsiveness of the detector to the polarization modes of GW signals and to clarify the corresponding characteristic regularities. In this paper, we calculate and analyze the sensitivity functions of 45 core geometric time-delay interferometry technique (TDI) combinations under the six polarization modes allowed by the metric gravity theory. The analysis is based on arbitrary second-generation TDI that can be independently linearly expanded by first-generation generators. It turns out that the sensitivity functions of 45 TDI combinations in different polarization modes are classified into exactly the same 11 categories, and there are obvious characteristic patterns in the asymptotic behavior of these sensitivity functions. These results can help to measure the GW polarization states, understand the nature of fields beyond the gravitational field, and provide some support for distinguishing gravitational theories. In addition, the sensitivity functions of multi-type TDI combinations can be applied to the parameter estimation to improve the localization accuracy of all-sky GW sources.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"4 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142888920","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

Exploring perturbative constraints in higher-order curvature gravity theories 探索高阶曲率重力理论中的微扰约束

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-24 DOI: 10.1088/1361-6382/ad9ce1

Daniel Molano and Pedro Bargueño

引用次数: 0

Experimental design for testing local Lorentz invariance violation in gravity 检验引力局部洛伦兹不变性破坏的实验设计

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-24 DOI: 10.1088/1361-6382/ad9c0c

Jia-Rui Li, Yu-Jie Tan, Tao Jin, Wei-Sheng Huang, Hao Huang, Cheng-Gang Qin and Cheng-Gang Shao

引用次数: 0

Metric symmetry by design in general relativity 广义相对论中设计的度量对称

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-24 DOI: 10.1088/1361-6382/ad9f15

Viktor T Toth

引用次数: 0

Amplitude stability research and experimental investigation of the actuation circuit of the inertial sensor for space gravitational wave detection 空间引力波探测惯性传感器驱动电路幅值稳定性研究与实验研究

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2024-12-24 DOI: 10.1088/1361-6382/ad9c0d

Jiawei Zhang, Peilong Yu, Shuyang Lin, Qinbo Ma, Zhe Han and Jianping Huang

引用次数: 0