arXiv - PHYS - General Relativity and Quantum Cosmology最新文献_第9页

Primordial Black Holes in the Solar System 太阳系中的原始黑洞

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-06 DOI: arxiv-2409.04518

Valentin Thoss, Andreas Burkert

引用次数: 0

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-06 DOI: arxiv-2409.04281

R. F. Aranha, H. P. de Oliveira

引用次数: 0

Paraxial wave equation of light bundles: Gaussian beams and caustic avoidance 光束的旁轴波方程：高斯光束和避免苛求

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-06 DOI: arxiv-2409.04659

Nezihe Uzun

{"title":"Paraxial wave equation of light bundles: Gaussian beams and caustic avoidance","authors":"Nezihe Uzun","doi":"arxiv-2409.04659","DOIUrl":"https://doi.org/arxiv-2409.04659","url":null,"abstract":"Infinitesimal light bundles on curved spacetimes can be studied via a\u0000Hamiltonian formalism, similar to the Newtonian paraxial rays. In this work, we\u0000assign a classical wave function to a thin null bundle and study its evolution\u0000equation. This is achieved via the usage of the Schr\"odinger operators within\u0000a procedure analogous to the one in the semi-classical regime of quantum\u0000mechanics. The correspondence between the metaplectic operators and the\u0000symplectic phase space transformations of the geodesic deviation variables is\u0000at the core of our method. It allows for the introduction of unitary operators.\u0000We provide two solutions of the null bundle wave function which differ by their\u0000origin: (i) a point source, and (ii) a finite source. It is shown that while\u0000the former wave function includes the same information as the standard thin\u0000null bundle framework, the latter is a Gaussian beam. The Gaussianity of the\u0000intensity profile of our beam depends on the spacetime curvature and not on the\u0000random processes. We show that this beam avoids the caustics of an\u0000instantaneous wavefront. Our results are applicable for any spacetime and they\u0000can be used to model light propagation from coherent sources while averting the\u0000mathematical singularities of the standard thin null bundle formalism. This is\u0000especially relevant when estimating cosmological distances in a realistic\u0000inhomogeneous universe.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"399 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199225","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

Formation of stable wormhole solution with non-commutative geometry in the framework of $f(R,mathcal{L}_m, T)$ gravity 在$f(R,mathcal{L}_m, T)$引力框架下形成非交换几何的稳定虫洞方案

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-06 DOI: arxiv-2409.04172

Niklas Loewer, Moreshwar Tayde, P. K. Sahoo

{"title":"Formation of stable wormhole solution with non-commutative geometry in the framework of $f(R,mathcal{L}_m, T)$ gravity","authors":"Niklas Loewer, Moreshwar Tayde, P. K. Sahoo","doi":"arxiv-2409.04172","DOIUrl":"https://doi.org/arxiv-2409.04172","url":null,"abstract":"This research delves into the potential existence of traversable wormholes\u0000(WHs) within the framework of $f(R,mathcal{L}_m, T)$ gravity, a modification\u0000that includes the matter Lagrangian and the trace of the energy-momentum tensor\u0000with specific coupling strengths $alpha$ and $beta$. A thorough examination\u0000of WH solutions is undertaken using a constant redshift function in tandem with\u0000a linear $f(R,mathcal{L}_m, T)$ model. The analysis involves deriving WH shape\u0000functions based on non-commutative geometry, with a particular focus on\u0000Gaussian and Lorentzian matter distributions $rho$. Constraints on the\u0000coupling parameters are developed so that the shape function satisfies both the\u0000flaring-out and asymptotic flatness conditions. Moreover, for positive coupling\u0000parameters, violating the null energy condition (NEC) at the WH throat $r_0$\u0000demands the presence of exotic matter. For negative couplings, however, we find\u0000that exotic matter can be avoided by establishing the upper bound\u0000$beta+alpha/2<-frac{1}{rho r_0^2}-8pi$. Additionally, the effects of\u0000gravitational lensing are explored, revealing the repulsive force of our\u0000modified gravity for large negative couplings. Lastly, the stability of the\u0000derived WH solutions is verified using the Tolman-Oppenheimer-Volkoff (TOV)\u0000formalism.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199079","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

Strong gravitational lensing in a Kerr black hole within Quantum Einstein Gravity 量子爱因斯坦引力中克尔黑洞的强引力透镜效应

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-06 DOI: arxiv-2409.03975

Chen-Hao Xie, Yu Zhang, Bo-Li Liu, Peng-Fei Duan, Yu-Li Lou

{"title":"Strong gravitational lensing in a Kerr black hole within Quantum Einstein Gravity","authors":"Chen-Hao Xie, Yu Zhang, Bo-Li Liu, Peng-Fei Duan, Yu-Li Lou","doi":"arxiv-2409.03975","DOIUrl":"https://doi.org/arxiv-2409.03975","url":null,"abstract":"The detailed study of the strong gravitational lensing of a Kerr black hole\u0000within Quantum Einstein Gravity (QEG) is performed. We calculate the photon\u0000sphere, the deflection angle of light, and observables on the equatorial plane\u0000under the strong deflection limit in a vacuum. The presence of quantum effects\u0000reduces the radius of the photon sphere, the magnification, the position of\u0000relativistic images, and the time delays on the same side of the lens. However,\u0000it increases the strong deflection angle, the separations, and the time delays\u0000on the opposite side of the lens. By modeling M87* and Sgr A* as the Kerr black\u0000hole within QEG, we find that the time delays are more significant in M87*,\u0000while other observables are more pronounced in Sgr A*. Furthermore, we consider\u0000the influence of plasma on the gravitational lensing effect. Plasma causes an\u0000additional deflection of light, increasing the magnification, images position\u0000and the time delays, but decreasing the separations. More importantly, we\u0000calculate the time delays under the strong deflection limit in the presence of\u0000plasma, and they increase with higher plasma concentrations. Our research may\u0000help to evaluate the observational imprints left by such quantum effects in the\u0000propagation of light and the impact of plasma around black holes on\u0000gravitational lensing.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199081","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

Kerr Geodesics in horizon-penetrating Kerr coordinates: description in terms of Weierstrass functions 地平线穿透克尔坐标中的克尔大地线：用魏尔斯特拉斯函数描述

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-05 DOI: arxiv-2409.03722

Zuzanna Bakun, Angelika Łukanty, Anastasiia Untilova, Adam Cieślik, Patryk Mach

引用次数: 0

The anti-aligned spin of GW191109: glitch mitigation and its implications GW191109 的反对齐自旋：故障缓解及其影响

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-05 DOI: arxiv-2409.03912

Rhiannon Udall, Sophie Hourihane, Simona Miller, Derek Davis, Katerina Chatziioannou, Max Isi, Howard Deshong

{"title":"The anti-aligned spin of GW191109: glitch mitigation and its implications","authors":"Rhiannon Udall, Sophie Hourihane, Simona Miller, Derek Davis, Katerina Chatziioannou, Max Isi, Howard Deshong","doi":"arxiv-2409.03912","DOIUrl":"https://doi.org/arxiv-2409.03912","url":null,"abstract":"With a high total mass and an inferred effective spin anti-aligned with the\u0000orbital axis at the 99.9% level, GW191109 is one of the most promising\u0000candidates for a dynamical formation origin among gravitational wave events\u0000observed so far. However, the data containing GW191109 are afflicted with\u0000terrestrial noise transients, i.e., detector glitches, generated by the\u0000scattering of laser light in both LIGO detectors. We study the implications of\u0000the glitch(es) on the inferred properties and astrophysical interpretation of\u0000GW191109. Using time- and frequency-domain analysis methods, we isolate the\u0000critical data for spin inference to 35 - 40 Hz and 0.1 - 0.04 s before the\u0000merger in LIGO Livingston, directly coincident with the glitch. Using two\u0000models of glitch behavior, one tailored to slow scattered light and one more\u0000generic, we perform joint inference of the glitch and binary parameters. When\u0000the glitch is modeled as slow scattered light, the binary parameters favor\u0000anti-aligned spins, in agreement with existing interpretations. When more\u0000flexible glitch modeling based on sine-Gaussian wavelets is used instead, a\u0000bimodal aligned/anti-aligned solution emerges. The anti-aligned spin mode is\u0000correlated with a weaker inferred glitch and preferred by ~ 70 : 30 compared to\u0000the aligned spin mode and a stronger inferred glitch. We conclude that if we\u0000assume that the data are only impacted by slow scattering noise, then the\u0000anti-aligned spin inference is robust. However, the data alone cannot validate\u0000this assumption and resolve the anti-aligned spin and potentially dynamical\u0000formation history of GW191109.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199080","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

AI forecasting of higher-order wave modes of spinning binary black hole mergers 旋转双黑洞合并的高阶波模式的人工智能预测

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-05 DOI: arxiv-2409.03833

Victoria Tiki, Kiet Pham, Eliu Huerta

{"title":"AI forecasting of higher-order wave modes of spinning binary black hole mergers","authors":"Victoria Tiki, Kiet Pham, Eliu Huerta","doi":"arxiv-2409.03833","DOIUrl":"https://doi.org/arxiv-2409.03833","url":null,"abstract":"We present a physics-inspired transformer model that predicts the non-linear\u0000dynamics of higher-order wave modes emitted by quasi-circular, spinning,\u0000non-precessing binary black hole mergers. The model forecasts the waveform\u0000evolution from the pre-merger phase through the ringdown, starting with an\u0000input time-series spanning $ t in [-5000textrm{M}, -100textrm{M}) $. The\u0000merger event, defined as the peak amplitude of waveforms that include the $l =\u0000|m| = 2$ modes, occurs at $ t = 0textrm{M} $. The transformer then generates\u0000predictions over the time range $ t in [-100textrm{M}, 130textrm{M}] $. We\u0000produced training, evaluation and test sets using the NRHybSur3dq8 model,\u0000considering a signal manifold defined by mass ratios $ q in [1, 8] $; spin\u0000components $ s^z_{{1,2}} in [-0.8, 0.8] $; modes up to $l leq 4$, including\u0000the $(5,5)$ mode but excluding the $(4,0)$ and $(4,1)$ modes; and inclination\u0000angles $theta in [0, pi]$. We trained the model on 14,440,761 waveforms,\u0000completing the training in 15 hours using 16 NVIDIA A100 GPUs in the Delta\u0000supercomputer. We used 4 H100 GPUs in the DeltaAI supercomputer to compute,\u0000within 7 hours, the overlap between ground truth and predicted waveforms using\u0000a test set of 840,000 waveforms, finding that the mean and median overlaps over\u0000the test set are 0.996 and 0.997, respectively. Additionally, we conducted\u0000interpretability studies to elucidate the waveform features utilized by our\u0000transformer model to produce accurate predictions. The scientific software used\u0000for this work is released with this manuscript.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199082","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

Anisotropy of Nanohertz Gravitational Wave Background and Individual Sources from Supermassive Binary Black Holes: Probe of Cosmic Large Scale Structure 来自超大质量双黑洞的纳米赫兹引力波背景和单个源的各向异性：宇宙大尺度结构探测器

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-09 DOI: arxiv-2408.05043

Qing Yang, Xiao Guo, Zhoujian Cao, Xiaoyun Shao, Xi Yuan

{"title":"Anisotropy of Nanohertz Gravitational Wave Background and Individual Sources from Supermassive Binary Black Holes: Probe of Cosmic Large Scale Structure","authors":"Qing Yang, Xiao Guo, Zhoujian Cao, Xiaoyun Shao, Xi Yuan","doi":"arxiv-2408.05043","DOIUrl":"https://doi.org/arxiv-2408.05043","url":null,"abstract":"Several pulsar timing array (PTA) groups have recently claimed the detection\u0000of nanohertz gravitational wave (GW) background, but the origin of this GW\u0000signal remains unclear. Nanohertz GWs generated by supermassive binary black\u0000holes (SMBBHs) are one of the most important GW sources in the PTA band.\u0000Utilizing data from numerical cosmology simulation, we generate mock SMBBHs\u0000within the observable universe and treat them as PTA band GW sources. We\u0000present their statistical properties, and analyze the isotropic and anisotropic\u0000characteristics of the gravitational wave background (GWB) signal they produce.\u0000Specifically, we derive the characteristic amplitude and spectrum of the GWB\u0000signal, and calculate the angular power spectrum for both GW strains/energy\u0000density and the position distribution of GW sources. We predict that the\u0000angular power spectrum of GWB energy density has $C_1/C_0approx0.40pm0.32$,\u0000and $C_l/C_0simeq frac{1}{2(2l+1)}$ (for $l>1$). Furthermore, for the\u0000upcoming Chinese Pulsar Timing Array (CPTA) and Square Kilometre Array (SKA)\u0000PTA, we predict the spatial distribution, numbers and signal-to-noise ratio\u0000(SNR) distribution of individual GW sources that may be detected with SNR>8,\u0000and study the anisotropy property in the spatial distribution of these\u0000individual GW sources.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930020","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

Strong Gravitational Lensing by Bardeen Black Hole in Cloud of Strings 弦云中的巴丁黑洞产生的强引力透镜效应

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-09 DOI: arxiv-2408.05018

Bijendra Kumar Vishvakarma, Shubham Kala, Sanjay Siwach

引用次数: 0