arXiv - PHYS - General Relativity and Quantum Cosmology最新文献_第3页

Quasinormal Modes of Dilaton Black Holes: Analytic approximations 迪拉顿黑洞的准正常模式：分析近似

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-15 DOI: arxiv-2409.09872

Zainab Malik

引用次数: 0

Constraining matter bounce scenario from scalar-induced vector perturbations 从标量诱发的矢量扰动制约物质反弹情景

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-14 DOI: arxiv-2409.09458

Mian Zhu, Chao Chen

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Pure Lovelock Gravity regular black holes 纯洛弗洛克引力普通黑洞

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-14 DOI: arxiv-2409.09559

Milko Estrada, Rodrigo Aros

{"title":"Pure Lovelock Gravity regular black holes","authors":"Milko Estrada, Rodrigo Aros","doi":"arxiv-2409.09559","DOIUrl":"https://doi.org/arxiv-2409.09559","url":null,"abstract":"We present a new family of regular black holes (RBH) in Pure Lovelock\u0000gravity, where the energy density is determined by the gravitational vacuum\u0000tension, which varies for each value of $n$ in each Lovelock case. A notable\u0000feature of our model is that the regular solution closely resembles the vacuum\u0000solution before reaching the event horizon. For odd $n$, the transverse\u0000geometry is spherical, with phase transitions occurring during evaporation, and\u0000the final state of this process is a remnant. For even $n$, the transverse\u0000geometry in non trivial and corresponds to a hyperboloid. In the case of\u0000$d=2n+1$ with even $n$, we find an RBH without a dS core and no inner horizon\u0000(whose presence has been recently debated in the literature due to the question\u0000of whether its presence is unstable or not), and no phase transitions. For\u0000$d>2n+1$ with even $n$, the RBH possesses both an event horizon and a\u0000cosmological horizon and no inner horizon. The existence of the cosmological\u0000horizon arises without the usual requirement of a positive cosmological\u0000constant. From both numerical and analytical analysis, we deduce that as the\u0000event horizon expands and the cosmological horizon contracts, thermodynamic\u0000equilibrium is achieved in a remnant when the two horizons coincide.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250731","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

Existence of the Chapman-Enskog solution and its relation with first-order dissipative fluid theories 查普曼-恩斯科格解法的存在及其与一阶耗散流体理论的关系

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-13 DOI: arxiv-2409.08976

A. L. García-Perciante, A. R. Méndez, O. Sarbach

引用次数: 0

Hanging on the cliff: EMRI formation with local two-body relaxation and post-Newtonian dynamics 悬崖勒马：利用局部二体弛豫和后牛顿动力学形成 EMRI

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-13 DOI: arxiv-2409.09122

Davide Mancieri, Luca Broggi, Matteo Bonetti, Alberto Sesana

{"title":"Hanging on the cliff: EMRI formation with local two-body relaxation and post-Newtonian dynamics","authors":"Davide Mancieri, Luca Broggi, Matteo Bonetti, Alberto Sesana","doi":"arxiv-2409.09122","DOIUrl":"https://doi.org/arxiv-2409.09122","url":null,"abstract":"Extreme mass ratio inspirals (EMRIs) are anticipated to be primary\u0000gravitational wave sources for LISA (Laser Interferometer Space Antenna). They\u0000form in dense nuclear clusters when a compact object (CO) is captured by the\u0000central massive black holes (MBHs) due to frequent two-body interactions among\u0000orbiting objects. We present a novel Monte Carlo approach to evolve the\u0000post-Newtonian (PN) equations of motion of a CO orbiting an MBH accounting for\u0000two-body relaxation locally on the fly, without the assumption of\u0000orbit-averaging. We estimate the fraction $S(a_0)$ of EMRIs to total captures\u0000(including direct plunges, DPs) as a function of the initial semi-major axis\u0000$a_0$ for COs around MBHs of $M_bulletin[10^4,{rm\u0000M}_odot,4times10^6,{rm M}_odot]$. Previous results indicate\u0000$S(a_0)rightarrow 0$ at large $a_0$, with a sharp transition from EMRIs to DPs\u0000around a critical scale $a_{rm c}$. This notion has been recently challenged\u0000for low-mass MBHs, with EMRIs forming at $agg a_{rm c}$, the so-called\u0000\"cliffhangers''. Our simulations confirm their existence, at larger numbers\u0000than previously expected. Cliffhangers start to appear for\u0000$M_bulletlesssim3times 10^5,{rm M}_odot$ and can account for up to 55% of\u0000the overall EMRIs formed. We find $S(a_0)gg 0$ for $agg a_{rm c}$, reaching\u0000values as high as 0.6 for $M_bullet=10^4,{rm M}_odot$, much larger than\u0000previously found. We find that the PN description of the system greatly\u0000enhances the number of EMRIs by shifting $a_{rm c}$ to larger values at all\u0000MBH masses, and that the local treatment of relaxation significantly boosts the\u0000number of cliffhangers for small MBHs. Our work shows the limitations of\u0000standard assumptions for estimating EMRI formation rates, most importantly\u0000their dynamical models. Future estimates of rates and properties of EMRIs\u0000detectable by LISA should account for these improvements.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250785","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

Evaluating the gravitational wave detectability of globular clusters and the Magellanic Clouds for LISA 为 LISA 评估球状星团和麦哲伦云的引力波可探测性

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-13 DOI: arxiv-2409.09159

Wouter G. J. van Zeist, Gijs Nelemans, Simon F. Portegies Zwart, Jan J. Eldridge

{"title":"Evaluating the gravitational wave detectability of globular clusters and the Magellanic Clouds for LISA","authors":"Wouter G. J. van Zeist, Gijs Nelemans, Simon F. Portegies Zwart, Jan J. Eldridge","doi":"arxiv-2409.09159","DOIUrl":"https://doi.org/arxiv-2409.09159","url":null,"abstract":"We use the stellar evolution code BPASS and the gravitational wave simulation\u0000code LEGWORK to simulate populations of compact binaries that may be detected\u0000by the in-development space-based gravitational wave (GW) detector LISA.\u0000Specifically, we simulate the Magellanic Clouds and binary populations\u0000mimicking several globular clusters, neglecting dynamical effects. We find that\u0000the Magellanic Clouds would have a handful of detectable sources each, but for\u0000globular clusters the amount of detectable sources would be less than one. We\u0000compare our results to earlier research and find that our predicted numbers are\u0000several tens of times lower than calculations using the stellar evolution code\u0000BSE that take dynamical effects into account, but also calculations using the\u0000stellar evolution code SeBa for the Magellanic Clouds. This correlates with\u0000earlier research which compared BPASS models for GW sources in the Galactic\u0000disk with BSE models and found a similarly sized discrepancy. We analyse and\u0000explain this discrepancy as being caused by differences between the stellar\u0000evolution codes, particularly in the treatment of mass transfer and\u0000common-envelope events in binaries, where in BPASS mass transfer is more likely\u0000to be stable and tends to lead to less orbital shrinkage in the common-envelope\u0000phase than in other codes. This difference results in fewer compact binaries\u0000with periods short enough to be detected by LISA existing in the BPASS\u0000population. For globular clusters, we conclude that the impact of dynamical\u0000effects is uncertain from the literature, but the differences in stellar\u0000evolution have an effect of a factor of a few tens.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250733","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

Orbital precession and other properties of two-body motion in the presence of dark energy 暗能量存在下的轨道前冲和双体运动的其他特性

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-13 DOI: arxiv-2409.11427

Gennady S. Bisnovatyi-Kogan, Marco Merafina

引用次数: 0

Elucidating the z-dependence of the MOND acceleration (a_0) within the Scale Invariant Vacuum (SIV) paradigm 在尺度不变真空（SIV）范式中阐明 MOND 加速（a_0）的 z 依赖性

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-12 DOI: arxiv-2409.11425

Vesselin G. Gueorguiev

{"title":"Elucidating the z-dependence of the MOND acceleration (a_0) within the Scale Invariant Vacuum (SIV) paradigm","authors":"Vesselin G. Gueorguiev","doi":"arxiv-2409.11425","DOIUrl":"https://doi.org/arxiv-2409.11425","url":null,"abstract":"In a recent paper: ``On the time dependency of $a_0$\" the authors claim that\u0000they have tested ``one of the predictions of the Scale Invariant Vacuum (SIV)\u0000theory on MOND\" by studying the dependence of the Modified Newtonian Dynamics\u0000(MOND) acceleration at two data sets, low-$z$ ($3.2times10^{-4}le zle\u00003.2times10^{-2}$) and high-$z$ ($0.5le zle 2.5$). They claim ``both samples\u0000show a dependency of $a_0$ from $z$\". Here, the work mentioned above is\u0000revisited. The explicit analytic expression for the $z$-dependence of the $a_0$\u0000within the SIV theory is given. Furthermore, the first estimates of the\u0000$Omega_m$ within SIV theory give $Omega_{m}=0.28pm 0.04$ using the low-z\u0000data only, while a value of $Omega_{m}=0.055$ is obtained using both data\u0000sets. This much lower $Omega_m$ leaves no room for non-baryonic matter! Unlike\u0000in the mentioned paper above, the slope in the $z$-dependence of\u0000$A_0=log_{10}(a_0)$ is estimated to be consistent with zero Z-slope for the\u0000two data sets. Finally, the statistics of the data are consistent with the SIV\u0000predictions; in particular, the possibility of change in the sign of the slopes\u0000for the two data sets is explainable within the SIV paradigm; however, the\u0000uncertainty in the data is too big for the clear demonstration of a\u0000$z$-dependence yet.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250789","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

Charting the Nanohertz Gravitational Wave Sky with Pulsar Timing Arrays 用脉冲星定时阵列描绘纳赫兹引力波天空

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-12 DOI: arxiv-2409.07955

Reginald Christian Bernardo, Kin-Wang Ng

{"title":"Charting the Nanohertz Gravitational Wave Sky with Pulsar Timing Arrays","authors":"Reginald Christian Bernardo, Kin-Wang Ng","doi":"arxiv-2409.07955","DOIUrl":"https://doi.org/arxiv-2409.07955","url":null,"abstract":"In the summer of 2023, the pulsar timing arrays (PTAs) announced a compelling\u0000evidence for the existence of a nanohertz stochastic gravitational wave\u0000background (SGWB). Despite this breakthrough, however, several critical\u0000questions remain unanswered: What is the source of the signal? How can cosmic\u0000variance be accounted for? To what extent can we constrain nanohertz gravity?\u0000When will individual supermassive black hole binaries become observable? And\u0000how can we achieve a stronger detection? These open questions have spurred\u0000significant interests in PTA science, making this an opportune moment to\u0000revisit the astronomical and theoretical foundations of the field, as well as\u0000the data analysis techniques employed. In this review, we focus on the\u0000theoretical aspects of the SGWB as detected by PTAs. We provide a comprehensive\u0000derivation of the expected signal and its correlation, presented in a\u0000pedagogical manner, while also addressing current constraints. Looking ahead,\u0000we explore future milestones in the field, with detailed discussions on\u0000emerging theoretical considerations such as cosmic variance, the cumulants of\u0000the one- and two-point functions, subluminal gravitational waves, and the\u0000anisotropy and polarization of the SGWB.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199287","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

Effects of Dark Matter on the Spontaneous Scalarization in Neutron Stars 暗物质对中子星自发量子化的影响

arXiv - PHYS - General Relativity and Quantum Cosmology Pub Date : 2024-09-11 DOI: arxiv-2409.07328

Fahimeh Rahimi, Zeinab Rezaei

{"title":"Effects of Dark Matter on the Spontaneous Scalarization in Neutron Stars","authors":"Fahimeh Rahimi, Zeinab Rezaei","doi":"arxiv-2409.07328","DOIUrl":"https://doi.org/arxiv-2409.07328","url":null,"abstract":"Dark matter, an important portion of compact objects, can influence different\u0000phenomena in neutron stars. The spontaneous scalarization in the scalar-tensor\u0000gravity has been proposed for neutron stars. Here, we investigate the\u0000spontaneous scalarization in dark matter admixed neutron stars. Applying the\u0000dark matter equations of state, we calculate the structure of scalarized\u0000neutron stars containing dark matter. The dark matter equations of state are\u0000based on observational data from the rotational curves of galaxies and the\u0000fermionic self-interacting dark matter. Our results verify that the spontaneous\u0000scalarization is affected by the dark matter pressure in neutron stars.\u0000Depending on the central density of scalarized dark matter admixed neutron\u0000stars, the dark matter pressure alters the central scalar field. The increase\u0000of dark matter pressure in low-density scalarized stars amplifies the central\u0000scalar field. However, the pressure of dark matter in high-density scalarized\u0000stars suppresses the central scalar field. Our calculations confirm that the\u0000stars in the merger event GW170817 and in the low-mass X-ray binary 4U 1820-30\u0000can be scalarized dark matter admixed neutron stars.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199237","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