arXiv - PHYS - General Relativity and Quantum Cosmology最新文献_第10页

Spherically symmetric loop quantum gravity: Schwarzschild spacetimes with a cosmological constant 球对称环量子引力：具有宇宙常数的施瓦兹柴尔德时空

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-09 DOI: arxiv-2408.04925

Esteban Mato, Javier Olmedo, Sahil Saini

引用次数: 0

A New Approach for Calculation of Quasi-Normal Modes and Topological Charges of Regular Black Holes 计算正态黑洞准正态模式和拓扑电荷的新方法

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04704

MY Zhang, F Hosseinifar, H Chen, T Sathiyaraj, H Hassanabadi

引用次数: 0

Eccentric features in the gravitational wave phase of dynamically formed black hole binaries 动态形成的黑洞双星引力波相位的偏心特征

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04603

Kai Hendriks, Lorenz Zwick, Johan Samsing

{"title":"Eccentric features in the gravitational wave phase of dynamically formed black hole binaries","authors":"Kai Hendriks, Lorenz Zwick, Johan Samsing","doi":"arxiv-2408.04603","DOIUrl":"https://doi.org/arxiv-2408.04603","url":null,"abstract":"We study the gravitational wave (GW) phase shift arising from R{o}mer delay\u0000in binary black hole (BBH) mergers formed dynamically in three-body systems,\u0000where both the inner orbit of the merging binary and the outer orbit are\u0000eccentric. We provide a semi-analytical model and several analytical\u0000approximations that allow for fast evaluation of both the temporal evolution\u0000and the maximum value of the phase shift. The highest phase shifts occur when\u0000the binary merges close to the pericentre of the outer orbit, and can in this\u0000case be orders-of-magnitude larger compared to the circular limit. At high\u0000outer orbit eccentricities, the orbital curvature leaves distinct imprints onto\u0000the phase shift if the binary passes the outer pericentre during its inspiral.\u0000By comparing with phase-shifts measured in numerical chaotic 3-body\u0000scatterings, we show that our model accurately describes the observed phase of\u0000dynamically assembled binary systems in realistic astrophysical scenarios,\u0000providing a way to directly determine their formation channel via single GW\u0000observations.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930016","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

Optical Properties and Thermal Geometries of Hot NUT-Kerr-Newman-Kasuya-AdS Spacetime 热 NUT-Kerr-Newman-Kasuya-AdS 时空的光学特性和热几何学

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04365

M. Umair Shahzad, Nazek Alessa, Abdul Wahab, Rafda Rafique

{"title":"Optical Properties and Thermal Geometries of Hot NUT-Kerr-Newman-Kasuya-AdS Spacetime","authors":"M. Umair Shahzad, Nazek Alessa, Abdul Wahab, Rafda Rafique","doi":"arxiv-2408.04365","DOIUrl":"https://doi.org/arxiv-2408.04365","url":null,"abstract":"This paper is devoted to studying the optical and thermal geometrical\u0000properties of Hot, NUT-KerrNewman-Kasuya-AdS black hole (BH). This BH is\u0000characterized by the NUT charge and a parameter Q that comprises the electric\u0000and magnetic charge. We compute the image of the BH shadow in two types: 1) at\u0000infinity, 2) at specific limit by analytical approach. We also investigate the\u0000effect of Nut, spin, inclination angle, and cosmological constant on the shape\u0000of shadow. We analyze that for type 1, the shadow in increasing for higher\u0000values of NUT charge, the cosmological constant, rotation parameters, and\u0000inclination angle, while for type 2, by increasing these parameters, the\u0000circular symmetry of the image of the BH shadow variate. Moreover, we discuss\u0000well-known thermal geometries such as Weinhold, Ruppeiner, HPEM, and Quevedo\u0000case I & II spacetime. It is found that Ruppeiner , HPEM and Quevedo (II)\u0000formulations provide physical information about the microscopic structure as\u0000compared to Weinhold and Quevedo (I) geometries of Hot\u0000NUT-Kerr-Newman-Kasuya-AdS BH. Our findings provides distinctive\u0000characteristics in the shadow and thermal geometries of this BH as compare to\u0000other BH types.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930019","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

Higher-order effects in the dynamics of hierarchical triple systems. II. Second-order and dotriacontapole-order effects 分层三重系统动力学中的高阶效应。II.二阶效应和点尖端效应

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04411

Landen Conway, Clifford M. Will

{"title":"Higher-order effects in the dynamics of hierarchical triple systems. II. Second-order and dotriacontapole-order effects","authors":"Landen Conway, Clifford M. Will","doi":"arxiv-2408.04411","DOIUrl":"https://doi.org/arxiv-2408.04411","url":null,"abstract":"We analyze the long-term evolution of hierarchical triple systems in\u0000Newtonian gravity to second order in the quadrupolar perturbation parameter,\u0000and to sixth order in $epsilon = a/A$, the ratio of the semimajor axes of the\u0000inner and outer orbits. We apply the ``two-timescale'' method from applied\u0000mathematics to the Lagrange Planetary Equations for the inner and outer orbits,\u0000in which each osculating orbit element is split into an orbit averaged part\u0000that evolves on the long perturbative timescale, and an ``average-free'' part\u0000that is oscillatory in the orbital timescales. Averages over the two orbital\u0000timescales are performed using the well-known secular approximation. We also\u0000incorporate perturbative corrections to the relation between time and the\u0000orbital phases. We place no restrictions on the masses, on the relative orbit\u0000inclinations or on the eccentricities, beyond the requirement that the\u0000quadrupolar parameter and $epsilon$ both be small. The result is a complete\u0000set of long-timescale evolution equations for the averaged elements of the\u0000inner and outer orbits. At first order in perturbation theory, we obtain the\u0000dotriacontapole contributions explicitly at order $epsilon^6$. At second order\u0000in perturbation theory, i.e. quadratic in the quadrupole perturbation\u0000amplitude, we find contributions that scale as $epsilon^{9/2}$ (found in\u0000earlier work), $epsilon^{5}$, $epsilon^{11/2}$, and $epsilon^{6}$. At first\u0000perturbative order and dotriacontapole order, the two averaged semimajor axes\u0000are constant in time (and we prove that this holds to arbitrary multipole\u0000orders); but at second perturbative order, beginning at $O( epsilon^{5})$,\u0000they are no longer constant. Nevertheless we verify that the total averaged\u0000energy of the system is conserved, and we argue that this behavior is not\u0000incompatible with classical theorems on secular evolution of the semimajor\u0000axes.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"191 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141930023","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

Expanding covariant cosmography of the local Universe: incorporating the snap and axial symmetry 局域宇宙的膨胀协变宇宙学：纳入快变和轴对称性

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04333

Basheer Kalbouneh, Jessica Santiago, Christian Marinoni, Roy Maartens, Chris Clarkson, Maharshi Sarma

{"title":"Expanding covariant cosmography of the local Universe: incorporating the snap and axial symmetry","authors":"Basheer Kalbouneh, Jessica Santiago, Christian Marinoni, Roy Maartens, Chris Clarkson, Maharshi Sarma","doi":"arxiv-2408.04333","DOIUrl":"https://doi.org/arxiv-2408.04333","url":null,"abstract":"Studies show that the model-independent, fully non-perturbative covariant\u0000cosmographic approach is suitable for analyzing the local Universe $(zlesssim\u00000.1)$. However, accurately characterizing large and inhomogeneous mass\u0000distributions requires the fourth-order term in the redshift expansion of the\u0000covariant luminosity distance $d_L(z,boldsymbol{n})$. We calculate the\u0000covariant snap parameter $mathbb{S}$ and its spherical harmonic multipole\u0000moments using the matter expansion tensor and the evolution equations for\u0000lightray bundles. The fourth-order term adds 36 degrees of freedom, since the\u0000highest independent multipole of the snap is the 32-pole (dotriacontapole)\u0000$(ell=5)$. Including this term helps to de-bias estimations of the covariant\u0000deceleration parameter. Given that observations suggest axially symmetric\u0000anisotropies in the Hubble diagram for $z lesssim 0.1$ and theory shows that\u0000only a subset of multipoles contributes to the signal, we demonstrate that only\u000012 degrees of freedom are needed for a model-independent description of the\u0000local universe. We use an analytical axisymmetric model of the local Universe,\u0000with data that matches the Zwicky Transient Facility survey, in order to\u0000provide a numerical example of the amplitude of the snap multipoles and to\u0000forecast precision.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949353","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

Reconciling Early and Late Time Tensions with Reinforcement Learning 用强化学习调和早晚时间的紧张关系

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04204

Mohit K. Sharma, M. Sami

引用次数: 0

Wormholes in $f(R,T)$ gravity with variable equation of state 具有可变状态方程的 $f(R,T)$ 重力中的虫洞

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-08 DOI: arxiv-2408.04402

Sara Rastgoo, Foad Parsaei

引用次数: 0

The 230 GHz Variability of Numerical Models of Sagittarius A* II. The Physical Origins of the Variability 人马座 A* 数值模型的 230 GHz 变异性 II.变异的物理起源

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-07 DOI: arxiv-2408.04132

Ho-Sang Chan, Chi-kwan Chan

{"title":"The 230 GHz Variability of Numerical Models of Sagittarius A* II. The Physical Origins of the Variability","authors":"Ho-Sang Chan, Chi-kwan Chan","doi":"arxiv-2408.04132","DOIUrl":"https://doi.org/arxiv-2408.04132","url":null,"abstract":"We explored in Chan et al. 2024 how the ion-electron temperature ratio\u0000affects certain numerical models of Sagittarius A* (Sgr A*). Specifically, we\u0000studied these effects in magnetic-dominated regions in magnetic-arrested disk\u0000(MAD), focusing on the $3$-hour variability at $230$ GHz -- $M_{Delta T}$. In\u0000this study, we investigate how variations in electron temperature prescription\u0000parameter, $R_{rm Low}$, influence $M_{Delta T}$ by analyzing a series of\u0000general-relativistic raytracing (GRRT) snapshots. In certain black hole models\u0000with a spin $a > 0$, we discover that increasing $R_{rm Low}$ renders the\u0000photon ring more optically thick, obscuring the varying accretion flows that\u0000contribute to the variability. However, as $R_{rm Low}$ increases further, MAD\u0000flux eruptions become more pronounced, compensating for the decrease in\u0000$M_{Delta T}$. For models with a spin $a < 0$, although a higher $R_{rm Low}$\u0000also increases the optical thickness of the fluid, voids within the optically\u0000thick gas fail to cover the entire photon ring. Similarly, flux eruptions are\u0000more prominent as $R_{rm Low}$ increases further, contributing to the observed\u0000rise in $M_{Delta T}$ against $R_{rm Low}$. For black holes with $a approx\u00000$, although the effect of increasing optical depth is still present, their\u0000$230$ GHz light curves and hence $M_{Delta T}$ are insensitive to the changes\u0000in $R_{rm Low}$. Furthermore, we find that the variability of the $230$ GHz\u0000light curves at $R_{rm Low} = 1$ correlates with fluctuations in the internal\u0000energy of the gas near the black hole, indicating that unusual gas heating may\u0000be the source of significant $M_{Delta T}$ seen in simulations. Our findings\u0000highlight potential approaches for refining $M_{Delta T}$ to better align with\u0000observations when modelling Sgr A* or other low-luminosity active galactic\u0000nuclei.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141949438","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

f(R) Gravitation: Equivalence of Frames Upon a Conformal Transformation f(R) 引力：共形变换后的等效框架

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-08-07 DOI: arxiv-2408.04672

João Pedro Bravo

引用次数: 0