Classical and Quantum Gravity最新文献_第6页

A MIMO system identification approach for the longitudinal control of the filter cavity of the advanced virgo gravitational-wave detector 先进处女座引力波探测器滤光腔纵向控制的MIMO系统辨识方法

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-18 DOI: 10.1088/1361-6382/adb82b

E N Tapia San Martín, Y Guo, M Vardaro, Y Zhao, E Capocasa, R Flaminio and M Tacca

{"title":"A MIMO system identification approach for the longitudinal control of the filter cavity of the advanced virgo gravitational-wave detector","authors":"E N Tapia San Martín, Y Guo, M Vardaro, Y Zhao, E Capocasa, R Flaminio and M Tacca","doi":"10.1088/1361-6382/adb82b","DOIUrl":"https://doi.org/10.1088/1361-6382/adb82b","url":null,"abstract":"The sensitivity of the second generation ground-based gravitational-wave detectors is mostly limited by quantum noise (QN). The injection of frequency-dependent squeezed vacuum states into the output port of the interferometer has been shown to reduce QN across the entire detector bandwidth. Frequency dependent squeezed states are generated by reflecting a frequency independent squeezed states off a detuned optical cavity: the phase response of the cavity rotates the squeeze angle as a function of frequency. The precision of the longitudinal control of the such cavity, known as filter cavity, is one of the key parameters affecting the QN suppression factor. The target longitudinal control precision was achieved by simultaneously acting on both the cavity length and the frequency of the squeezing main laser. In this scenario, the analysis of this system requires a Multiple-Input Multiple-Output (MIMO) system model. In this work, we demonstrate that a MIMO model is required and show that a MIMO system identification technique is effective to characterize the system and improve its robustness. Ultimately we show that these techniques allow the design of robust filters that can keep the cavity residual length fluctuations below 1 pm, allowing for a QN reduction of 4.5 dB at high frequencies and 2 dB at low frequencies in the Advanced Virgo interferometer.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"183 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641080","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

Parametric solutions to the Kerr separatrix 克尔分离矩阵的参数解

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-17 DOI: 10.1088/1361-6382/adba36

Tammy Ng and Edward Teo

引用次数: 0

Automated determination of the end time of junk radiation in binary black hole simulations 双黑洞模拟中垃圾辐射结束时间的自动测定

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-17 DOI: 10.1088/1361-6382/adbc3e

Isabella G Pretto, Mark A Scheel, Saul A Teukolsky

{"title":"Automated determination of the end time of junk radiation in binary black hole simulations","authors":"Isabella G Pretto, Mark A Scheel, Saul A Teukolsky","doi":"10.1088/1361-6382/adbc3e","DOIUrl":"https://doi.org/10.1088/1361-6382/adbc3e","url":null,"abstract":"When numerically solving Einstein’s equations for the evolution of binary black holes, physical imperfections in the initial data manifest as a transient, high-frequency pulse of ‘junk radiation.’ This unphysical signal must be removed before the waveform can be used. Improvements in the efficiency of numerical simulations now allow waveform catalogs containing thousands of waveforms to be produced. Thus, an automated procedure for identifying junk radiation is required. To this end, we present a new algorithm based on the empirical mode decomposition (EMD) from the Hilbert–Huang transform. This approach allows us to isolate and measure the high-frequency oscillations present in the measured irreducible masses of the black holes. The decay of these oscillations allows us to estimate the time from which the junk radiation can be ignored. To make this procedure more precise, we propose three distinct threshold criteria that specify how small the contribution of junk radiation has to be before it can be considered negligible. We apply this algorithm to 3403 BBH simulations from the Simulating eXtreme Spacetime catalog to find appropriate values for the thresholds in the three criteria. We find that this approach yields reliable decay time estimates, i.e. when to consider the simulation physical, for <inline-formula>\u0000<tex-math><?CDATA $ gt $?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:mo>></mml:mo></mml:mrow></mml:math><inline-graphic xlink:href=\"cqgadbc3eieqn1.gif\"></inline-graphic></inline-formula>98.5% of the simulations studied. This demonstrates the efficacy of the EMD as a suitable tool to automatically isolate and characterize junk radiation in the simulation of binary black hole systems.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"55 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635570","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

Axial Bianchi I meets drifting extragalactic sources 轴向Bianchi I遇到漂流的河外源

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-14 DOI: 10.1088/1361-6382/adbda5

Thomas Schücker

引用次数: 0

C-metric in a (nut)shell （螺母）壳中的c -公制

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-13 DOI: 10.1088/1361-6382/adbc3f

Cameron R D Bunney and Robert B Mann

{"title":"C-metric in a (nut)shell","authors":"Cameron R D Bunney and Robert B Mann","doi":"10.1088/1361-6382/adbc3f","DOIUrl":"https://doi.org/10.1088/1361-6382/adbc3f","url":null,"abstract":"We present a comprehensive study of the C-metric in dimensions, placing it within a shell of stress energy and matching it to an exterior vacuum anti-de Sitter metric. The C-metric is not circularly symmetric and hence neither are the constructed shells, which instead take on a cuspoidal or teardrop shape. We interpret the stress energy of the shells as a perfect fluid, calculating the energy density and pressure. For accelerating particles (Class I), we find the stress energy is concentrated on the part of shell farthest from the direction of acceleration and always respects the strong and weak energy conditions. For accelerating black holes (Class I , II, and III), the shell stress energy may either respect or violate the energy conditions depending on the parameter of the exterior metric—between the two regimes lies a critical value of the external parameter for which the shell stress energy vanishes, leading to new solutions of Einstein’s field equations, which fall into three categories: an accelerated black hole pulled by a finite-length string with a point particle at the other end, an accelerated black hole pushed by a finite-length strut with a point particle at the other end, and an accelerated black hole pushed from one side by a finite-length strut and pulled from the other by a finite-length string, each with a point particle at the other end.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"11 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143607788","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

The impact of an antisymmetric tensor on charged black holes: evaporation process, geodesics, deflection angle, scattering effects and quasinormal modes 反对称张量对带电黑洞的影响：蒸发过程、测地线、偏转角、散射效应和准正态模式

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-12 DOI: 10.1088/1361-6382/adbb4f

A A Araújo Filho, N Heidari, J A A S Reis and H Hassanabadi

引用次数: 0

Cosmic inflation prevents singularity formation in collapse into a Hayward black hole 宇宙膨胀阻止了奇点在坍缩成海沃德黑洞时的形成

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-12 DOI: 10.1088/1361-6382/adbc40

Michał Bobula

引用次数: 0

Fighting Newtonian noise with gradient-based optimization at the Einstein Telescope 在爱因斯坦望远镜上用梯度优化对抗牛顿噪声

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-11 DOI: 10.1088/1361-6382/adb898

Patrick Schillings and Johannes Erdmann

{"title":"Fighting Newtonian noise with gradient-based optimization at the Einstein Telescope","authors":"Patrick Schillings and Johannes Erdmann","doi":"10.1088/1361-6382/adb898","DOIUrl":"https://doi.org/10.1088/1361-6382/adb898","url":null,"abstract":"Newtonian noise in gravitational wave detectors originates from density fluctuations in the vicinity of the interferometer mirrors. At the Einstein Telescope, this noise source is expected to be dominant for low frequencies. Its impact is proposed to be reduced with the help of an array of seismometers that will be placed around the interferometer endpoints. We reformulate and implement the problem of finding the optimal seismometer positions in a differentiable way. We then explore the use of first-order gradient-based optimization for the design of the seismometer array for 1 Hz and 10 Hz and compare its performance and computational cost to two metaheuristic algorithms. For 1 Hz, we introduce a constraint term to prevent unphysical optimization results in the gradient-based method. In general, we find that it is an efficient strategy to initialize the gradient-based optimizer with a fast metaheuristic algorithm. For a small number of seismometers, this strategy results in approximately the same noise reduction as with the metaheuristics. For larger numbers of seismometers, gradient-based optimization outperforms the two metaheuristics by a factor of 2.25 for the faster of the two and a factor of 1.4 for the other one, which is significantly outperformed by gradient-based optimization in terms of computational efficiency.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"38 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143589903","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

Spurious solar-wind effects on acceleration noise in LISA Pathfinder 伪太阳风对LISA探路者加速噪声的影响

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-10 DOI: 10.1088/1361-6382/adb538

Arnold Tianyi Yang, Indie Desiderio-Sloane and Grant David Meadors

{"title":"Spurious solar-wind effects on acceleration noise in LISA Pathfinder","authors":"Arnold Tianyi Yang, Indie Desiderio-Sloane and Grant David Meadors","doi":"10.1088/1361-6382/adb538","DOIUrl":"https://doi.org/10.1088/1361-6382/adb538","url":null,"abstract":"Spurious solar-wind effects are a potential noise source in future Laser Interferometer Space Antenna (LISA) measurements. One noise coupling mechanism is constrained by estimating solar-wind effects on acceleration noise in LISA Pathfinder (LPF). While LISA is designed for drag-free differential measurement, predicting the realistic impact both bounds the operational environment and assesses whether LISA could provide serendipitous space-weather observations. Data from NASA’s Advanced Composition Explorer (ACE), situated at the L1 Lagrange point, serves as a reliable source of solar-wind data. The data sets are compared over the 114 d time period from 1 March 2016 to 23 June 2016. This period gives the longest readily-available open data set, without interference from other commissioning activities. To evaluate space weather effects, the data from both satellites are formatted, gap-filled/interpolated, and fast-Fourier transformed for amplitude spectral density and coherence comparisons. Solar wind effects are not seen in a coherence plot between LPF and ACE; modest coherence in the planned LISA observational frequency band can be attributed to chance. This result indicates that measurable correlation due to solar-wind acceleration noise over 3 month timescales will be a negligible noise source. LISA is unlikely to inform solar wind measurements routinely. Another source of noise from the Sun, solar radiation pressure, is estimated to impart greater acceleration noise, but has yet to be analyzed.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"2 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582684","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

Local coordinates and motion of a test particle in the McVittie spacetime McVittie时空中测试粒子的局部坐标和运动

IF 3.5 3区物理与天体物理

Classical and Quantum Gravity Pub Date : 2025-03-07 DOI: 10.1088/1361-6382/adb7b4

Vishal Jayswal and Sergei M Kopeikin

引用次数: 0