arXiv - PHYS - General Relativity and Quantum Cosmology最新文献_第6页

Black hole-neutron star binaries with high spins and large mass asymmetries: I. Properties of quasi-equilibrium sequences 具有高自旋和大质量不对称的黑洞-中子星双星：I. 准平衡序列的特性

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-10 DOI: arxiv-2409.06767

Konrad Topolski, Samuel Tootle, Luciano Rezzolla

{"title":"Black hole-neutron star binaries with high spins and large mass asymmetries: I. Properties of quasi-equilibrium sequences","authors":"Konrad Topolski, Samuel Tootle, Luciano Rezzolla","doi":"arxiv-2409.06767","DOIUrl":"https://doi.org/arxiv-2409.06767","url":null,"abstract":"Black hole - neutron star (BHNS) mergers are a promising target of current\u0000gravitational-wave (GW) and electromagnetic (EM) searches, being the putative\u0000origin of ultra-relativistic jets, gamma-ray emission, and r-process\u0000nucleosynthesis. However, the possibility of any EM emission accompanying a GW\u0000detection crucially depends on the amount of baryonic mass left after the\u0000coalescence, i.e. whether the neutron star (NS) undergoes a `tidal disruption'\u0000or `plunges' into the black hole (BH) while remaining essentially intact. As\u0000the first of a series of two papers, we here report the most systematic\u0000investigation to date of quasi-equilibrium sequences of initial data across a\u0000range of stellar compactnesses $mathcal{C}$, mass ratios $q$, BH spins\u0000$chi_{_{rm BH}}$, and equations of state satisfying all present observational\u0000constraints. Using an improved version of the elliptic initial-data solver\u0000FUKA, we have computed more than $1000$ individual configurations and estimated\u0000the onset of mass-shedding or the crossing of the innermost stable circular\u0000orbit in terms of the corresponding characteristic orbital angular velocities\u0000$Omega_{_{rm MS}}$ and $Omega_{_{rm ISCO}}$ as a function of $mathcal{C}, q$, and $chi_{_{rm BH}}$. To the\u0000best of our knowledge, this is the first time that the dependence of these\u0000frequencies on the BH spin is investigated. In turn, by setting $Omega_{_{rm\u0000MS}} = Omega_{_{rm ISCO}}$ it is possible to determine the separatrix between\u0000the `tidal disruption' or `plunge' scenarios as a function of the fundamental\u0000parameters of these systems, namely, $q, mathcal{C}$, and $chi_{_{rm BH}}$.\u0000Finally, we present a novel analysis of quantities related to the tidal forces\u0000in the initial data and discuss their dependence on spin and separation.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Blind source separation in 3rd generation gravitational-wave detectors 第三代引力波探测器的盲源分离

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-10 DOI: arxiv-2409.06458

Francesca Badaracco, Biswajit Banerjee, Marica Branchesi, Andrea Chincarini

引用次数: 0

A Binary Neutron Star Merger Search Pipeline Powered by Deep Learning 深度学习驱动的双中子星合并搜索管道

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-10 DOI: arxiv-2409.06266

Alistair McLeod, Damon Beveridge, Linqing Wen, Andreas Wicenec

{"title":"A Binary Neutron Star Merger Search Pipeline Powered by Deep Learning","authors":"Alistair McLeod, Damon Beveridge, Linqing Wen, Andreas Wicenec","doi":"arxiv-2409.06266","DOIUrl":"https://doi.org/arxiv-2409.06266","url":null,"abstract":"Gravitational waves are now routinely detected from compact binary mergers,\u0000with binary neutron star mergers being of note for multi-messenger astronomy as\u0000they have been observed to produce electromagnetic counterparts. Novel search\u0000pipelines for these mergers could increase the combined search sensitivity, and\u0000could improve the ability to detect real gravitational wave signals in the\u0000presence of glitches and non-stationary detector noise. Deep learning has found\u0000success in other areas of gravitational wave data analysis, but a sensitive\u0000deep learning-based search for binary neutron star mergers has proven elusive\u0000due to their long signal length. In this work, we present a deep learning\u0000pipeline for detecting binary neutron star mergers. By training a convolutional\u0000neural network to detect binary neutron star mergers in the signal-to-noise\u0000ratio time series, we concentrate signal power into a shorter and more\u0000consistent timescale than strain-based methods, while also being able to train\u0000our network to be robust against glitches. We compare our pipeline's\u0000sensitivity to the three offline detection pipelines using injections in real\u0000gravitational wave data, and find that our pipeline has a comparable\u0000sensitivity to the current pipelines below the 1 per 2 months detection\u0000threshold. Furthermore, we find that our pipeline can increase the total number\u0000of binary neutron star detections by 12% at a false alarm rate of 1 per 2\u0000months. The pipeline is also able to successfully detect the two binary neutron\u0000star mergers detected so far by the LIGO-Virgo-KAGRA collaboration, GW170817\u0000and GW190425, despite the loud glitch present in GW170817.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cosmological gravity on all scales IV: 3x2pt Fisher forecasts for pixelised phenomenological modified gravity 所有尺度上的宇宙引力 IV：像素化现象学修正引力的 3x2pt Fisher 预测

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-10 DOI: arxiv-2409.06569

Sankarshana Srinivasan, Daniel B Thomas, Peter L. Taylor

{"title":"Cosmological gravity on all scales IV: 3x2pt Fisher forecasts for pixelised phenomenological modified gravity","authors":"Sankarshana Srinivasan, Daniel B Thomas, Peter L. Taylor","doi":"arxiv-2409.06569","DOIUrl":"https://doi.org/arxiv-2409.06569","url":null,"abstract":"Stage IV large scale structure surveys are promising probes of gravity on\u0000cosmological scales. Due to the vast model-space in the modified gravity\u0000literature, model-independent parameterisations represent useful and scalable\u0000ways to test extensions of $Lambda$CDM. In this work we use a recently\u0000validated approach of computing the non-linear $3times 2$pt observables in\u0000modified gravity models with a time-varying effective gravitational constant\u0000$mu$ and a gravitational slip $eta$ that is binned in redshift to produce\u0000Fisher forecasts for an LSST Y10-like survey. We also include in our modelling\u0000an effective nulling scheme for weak-lensing by applying the BNT transformation\u0000that localises the weak-lensing kernel enabling well-informed scale cuts. We\u0000show that the combination of improved non-linear modelling and better control\u0000of the scales that are modelled/cut yields high precision constraints on the\u0000cosmological and modified gravity parameters. We find that 4 redshift bins for\u0000$mu$ of width corresponding to equal incremental $Lambda$CDM growth is\u0000optimal given the state-of-the-art modelling and show how the BNT\u0000transformation can be used to mitigate the impact of small-scale systematic\u0000effects, such as baryonic feedback.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Use Model Averaging instead of Model Selection in Pulsar Timing 在脉冲星计时中使用模型平均法而不是模型选择法

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.06050

Rutger van Haasteren

{"title":"Use Model Averaging instead of Model Selection in Pulsar Timing","authors":"Rutger van Haasteren","doi":"arxiv-2409.06050","DOIUrl":"https://doi.org/arxiv-2409.06050","url":null,"abstract":"Over the past decade and a half, adoption of Bayesian inference in pulsar\u0000timing analysis has led to increasingly sophisticated models. The recent\u0000announcement of evidence for a stochastic background of gravitational waves by\u0000various pulsar timing array projects highlighted Bayesian inference as a\u0000central tool for parameter estimation and model selection. Despite its success,\u0000Bayesian inference is occasionally misused in the pulsar timing community. A\u0000common workflow is that the data is analyzed in multiple steps: a first\u0000analysis of single pulsars individually, and a subsequent analysis of the whole\u0000array of pulsars. A mistake that is then sometimes introduced stems from using\u0000the posterior distribution to craft the prior for the analysis of the same data\u0000in a second step, a practice referred to in the statistics literature as\u0000``circular analysis.'' This is done to prune the model for computational\u0000efficiency. Multiple recent high-profile searches for gravitational waves by\u0000pulsar timing array (PTA) projects have this workflow. This letter highlights\u0000this error and suggests that Spike and Slab priors can be used to carry out\u0000model averaging instead of model selection in a single pass. Spike and Slab\u0000priors are proved to be equal to Log-Uniform priors.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Measuring the speed of light with cosmological observations: current constraints and forecasts 用宇宙学观测测量光速：当前的制约因素和预测

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.05838

Jaiane Santos, Carlos Bengaly, Jonathan Morais, Rodrigo S. Gonçalves

引用次数: 0

Current density induced by a cosmic string in de Sitter spacetime in the presence of two flat boundaries 德西特时空中的宇宙弦在存在两个平面边界时诱导的电流密度

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.05691

W. Oliveira dos Santos, H. F. Santana Mota, E. R. Bezerra de Mello

{"title":"Current density induced by a cosmic string in de Sitter spacetime in the presence of two flat boundaries","authors":"W. Oliveira dos Santos, H. F. Santana Mota, E. R. Bezerra de Mello","doi":"arxiv-2409.05691","DOIUrl":"https://doi.org/arxiv-2409.05691","url":null,"abstract":"In this paper, we investigate the vacuum bosonic current density induced by a\u0000carrying-magnetic-flux cosmic string in a $(D+1)$-de Sitter spacetime\u0000considering the presence of two flat boundaries perpendicular to it. In this\u0000setup, the Robin boundary conditions are imposed on the scalar charged quantum\u0000field on the boundaries. The particular cases of Dirichlet and Neumann boundary\u0000conditions are studied separately. Due to the coupling of the quantum scalar\u0000field with the classical gauge field, corresponding to a magnetic flux running\u0000along the string's core, a nonzero vacuum expectation value for the current\u0000density operator along the azimuthal direction is induced. The two boundaries\u0000divide the space in three regions with different properties of the vacuum\u0000states. In this way, our main objective is to calculate the induced currents in\u0000these three regions. In order to develop this analysis we calculate, for both\u0000regions, the positive frequency Wightman functions. Because the vacuum bosonic\u0000current in dS space has been investigated before, in this paper we consider\u0000only the contributions induced by the boundaries. We show that for each region\u0000the azimuthal current densities are odd functions of the magnetic flux along\u0000the string. To probe the correctness of our results, we take the particular\u0000cases and analyze some asymptotic limits of the parameters of the model. Also\u0000some graphs are presented exhibiting the behavior of the current with relevant\u0000physical parameter of the system.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Strange Quark Stars and Condensate Dark Stars in Bumblebee Gravity 大黄蜂引力中的奇异夸克星和凝聚暗星

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.05801

Grigoris Panotopoulos, Ali Övgün

引用次数: 0

Gravitational lensing and shadows from thin-disks in Loop Quantum Gravity self-dual black holes 环量子引力自双黑洞中的引力透镜和薄盘阴影

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.05371

David J. Patiño Pomares, Diego Rubiera-Garcia

{"title":"Gravitational lensing and shadows from thin-disks in Loop Quantum Gravity self-dual black holes","authors":"David J. Patiño Pomares, Diego Rubiera-Garcia","doi":"arxiv-2409.05371","DOIUrl":"https://doi.org/arxiv-2409.05371","url":null,"abstract":"We analyze gravitational lensing and their cast images from thin-disks in\u0000shadow observations of a family of spherically symmetric black hole solutions\u0000previously derived within the framework of Loop Quantum Gravity. Such black\u0000holes depend on two parameters (besides the mass of the black hole itself), $P$\u0000and $a_0$, the latter imbuing the configurations with an interior wormhole\u0000structure. Using the bounds from the Event Horizon Telescope regarding the\u0000shadow's radius of Sgr A$^*$ that constrain the parameter $P lesssim\u00000.08(2sigma)$ (at $a_0=0$), we study the modifications to weak and strong\u0000gravitational lensing induced by these geometries as compared to the\u0000Schwarzschild black hole within this range. In particular, we discuss several\u0000observables in the strong field regime related to the luminosity decay, the\u0000angular separation, and the flux ratio between multiples images of the source.\u0000Furthermore, we consider the cast images of these black holes when illuminated\u0000by a geometrically and optically thin accretion disk according to several\u0000semi-analytic profiles for the disk's emission.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Polarized Image of a Synchrotron-emitting Ring in Einstein-Maxwell-scalar Theory 爱因斯坦-麦克斯韦-标量理论中同步辐射环的偏振图像

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-09 DOI: arxiv-2409.05304

Yiqian Chen, Lang Cheng, Peng Wang, Haitang Yang

引用次数: 0