A possible detection of sub-solar mass ultra-compact objects would lead to new perspectives on the existence of black holes that are not of astrophysical origin and/or pertain to formation scenarios of exotic ultra-compact objects. Both possibilities open new perspectives for better understanding of our universe. In this work, we investigate the significance of detection of sub-solar mass binaries with components mass in the range: $10^{-2} M_\odot$ up to 1$M_\odot$, within the expected sensitivity of the ground-based gravitational waves detectors of third-generation, viz., the Einstein Telescope (ET) and the Cosmic Explorer (CE). Assuming a minimum of amplitude signal-to-noise ratio for detection, viz., $ρ= 8$, we find that the maximum horizon distances for an ultra-compact binary system with components mass $10^{-2} \, M_\odot$ and 1$M_\odot$ are 40 Mpc and 1.89 Gpc, respectively, for ET, and 125 Mpc and 5.8 Gpc, respectively, for CE. Other cases are also presented in the text. We derive the merger rate, and discuss consequences on the abundances of primordial black hole (PBH), $f_{\rm PBH}$. Considering the entire mass range [$10^{-2}$ - 1]$M_\odot$, we find $f_{\rm PBH} < 0.70$ ($<$ $0.06$) for ET (CE), respectively.
We determine the ability of Cosmic Explorer, a proposed third-generation gravitational-wave observatory, to detect eccentric binary neutron stars and to measure their eccentricity. We find that for a matched-filter search, template banks constructed using binaries in quasi-circular orbits are effectual for eccentric neutron star binaries with $e_{7} \leq 0.004$ ($e_{7} \leq 0.003$) for CE1 (CE2), where $e_7$ is the binary's eccentricity at a gravitational-wave frequency of 7~Hz. We show that stochastic template placement can be used to construct a matched-filter search for binaries with larger…
Overlap reduction functions for a polarized stochastic gravitational-wave background in the Einstein Telescope-Cosmic Explorer and the LISA-Taiji networks
本文将基于球谐展开的重叠减少函数计算方法推广到第三代地基 Einstein Telescope-Cosmic Explorer 网络及 LISA-Taiji 空间联合任务，以分析极化随机引力波背景。
The neutron star-black hole binary (NSBH) system has been considered one of the promising detection candidates for ground-based gravitational-wave (GW) detectors such as LIGO and Virgo. The tidal effects of neutron stars (NSs) are imprinted on the GW signals emitted from NSBHs as well as binary neutron stars. In this work, we study how accurately the parameter $λ_{\rm NS}$ can be measured in GW parameter estimation for NSBH signals. We set the parameter range for the NSBH sources to $[4M_{\odot}, 10M_{\odot}]$ for the black hole mass, $[1M_{\odot}, 2M_{\odot}]$ for the NS mass, and $[-0.9, 0.9…
Inferring the role of binary neutron star mergers in r-process nucleosynthesis with multi-messenger observations using Cosmic Explorer and Einstein Telescope
Institute of Physics, University of Greifswald（格赖夫斯瓦尔德大学物理研究所）；Department of Astronomy & Astrophysics, Tata Institute of Fundamental Research（塔塔基础研究院天文学与天体物理学系）
The existence of primordial black holes (PBHs), which may form from the collapse of matter overdensities shortly after the Big Bang, is still under debate. Among the potential signatures of PBHs are gravitational waves (GWs) emitted from binary black hole (BBH) mergers at redshifts $z\gtrsim 30$, where the formation of astrophysical black holes is unlikely. Future ground-based GW detectors, Cosmic Explorer and Einstein Telescope, will be able to observe equal-mass BBH mergers with total mass of $\mathcal{O}(10-100)~M_{\odot}$ at such distances. In this work, we investigate whether the redshift…
The third-generation ground-based gravitational-wave (GW) detector, Cosmic Explorer (CE), is scheduled to start its observation in the 2030s. In this paper, we make a forecast for cosmological parameter estimation with gravitational-wave standard siren observation from the CE. We use the simulated GW standard siren data of CE to constrain the $Λ$CDM, $w$CDM and CPL models. We combine the simulated GW data with the current cosmological electromagnetic observations including the latest cosmic microwave background anisotropies data from Planck, the optical baryon acoustic oscillation measurements…
We study gravitational waves emitted by a binary system of non-spinning bodies in a quasi-circular inspiral within the framework of Einstein-aether theory. In particular, we compute explicitly and analytically the expressions for the time-domain and frequency-domain waveforms, gravitational wave polarizations, and response functions for both ground- and space-based detectors in the post-Newtonian approximation. We find that, when going beyond leading-order in the post-Newtonian approximation, the non-Einsteinian polarization modes contain terms that depend on both the first and the second harm…
We present the prospects for the pre-merger detection and localization of binary neutron star mergers with third generation gravitational-wave observatories. We consider a wide variety of gravitational-wave networks which may be operating in the 2030's and beyond; these networks include up to two Cosmic Explorer sites, the Einstein Telescope, and continued observation with the existing second generation ground-based detectors. For a fiducial local merger rate of 300 Gpc$^{-3}$yr$^{-1}$, we find that the Einstein Telescope on its own is able to detect 6 and 2 sources per year at 5 and 30 minute…
We propose a novel method to test the consistency of the multipole moments of compact binary systems with the predictions of General Relativity (GR). The multipole moments of a compact binary system, known in terms of symmetric and trace-free tensors, are used to calculate the gravitational waveforms from compact binaries within the post-Newtonian (PN) formalism. For nonspinning compact binaries, we derive the gravitational wave phasing formula, in the frequency domain, parametrizing each PN order term in terms of the multipole moments which contribute to that order. Using GW observations, thi…
Detectability and Parameter Estimation for Einstein Telescope Configurations with GWJulia
Università degli Studi di Padova（帕多瓦大学）；INFN Sezione di Padova（意大利国家核物理研究所帕多瓦分部）；LUTH, UMR 8102 CNRS, Observatoire de Paris, PSL Research University, Université Paris Diderot（巴黎天文台理论天体物理学实验室）；Instituto de Estructura de la Materia (IEM), CSIC（西班牙高等科学研究理事会物质结构研究所）；CERN, Theoretical Physics Department（欧洲核子研究中心理论物理部）；Università di Pisa（比萨大学）；INFN, Sezione di Pisa（意大利国家核物理研究所比萨分部）
Gravitational waveforms from inspiraling compact binaries in quadratic gravity and their parameterized post-Einstein characterization
Universidade Federal do Espı́rito Santo（圣埃斯皮里图联邦大学）；Universidade Federal do Rio Grande do Norte（北里奥格兰德联邦大学）；Centro Brasileiro de Pesquisas Fı́sicas (CBPF)（巴西物理研究中心）
该研究在二次引力框架下分析了紧凑二元系统 inspiral 阶段的引力波形，并将其偏离广义相对论的特征嵌入到 PPE 框架中，以约束理论参数并提升约束精度。
Cosmology with the lights off: Standard sirens in the Einstein Telescope era
我们探索约束宇宙学的前景，利用引力波（GW）观测的中子星双星的建议爱因斯坦望远镜（ET），利用狭窄的中子星质量函数。双中子星（DNS）双星预计将成为先进LIGO“第一束光”后探测到的第一批源之一，预计在先进时代每年将以几十个的速度被探测到。然而，拟议中的ET每年可以编目数万人。将测得的源红移分布与GW网络距离测定相结合，不仅可以精确测量背景宇宙学参数，而且可以深入了解这些DNS系统的天体物理性质。特别感兴趣的将是探测DNS-二进制创建和随后的合并之间的延迟时间的分布，以及ET的探测范围内的恒星形成率密度的演变。在保持H_0、Ω_{m，0}和Ω_{Λ，0}不变的情况下，我们研究了暗能量状态方程参数恢复的精度，发现只要检测到10^5个DNS双星，我们就可以将这些参数限制到与未来CMB+BAO+SNIa测量的预测限制相似的精度。此外，建模合并延迟时间分布的幂律，和恒星形成率（SFR）密度的参数化版本的Porciani和Madau SF 2模型，我们发现，相关的天体物理参数被限制在10%以内。所有参数精密度均按1/sqrt（N）缩放，其中N是编目检测的数量。我们还研究了精度如何随着宇宙的内在基本属性和网络的距离（可能受到探测器低频截止的影响）而变化。
Modified gravitational wave propagation is a smoking gun of modifications of gravity at cosmological scales, and can be the most promising observable for testing such theories. The observation of gravitational waves (GW) in recent years has allowed us to start probing this effect, and here we briefly review two promising ways of testing it. We will show that, already with the current network of detectors, it is possible to reach an interesting accuracy in the estimation of the $Ξ_0$ parameter (that characterizes modified gravitational wave propagation, with $Ξ_{0, {\rm GR}} = 1$) and with next…
Dynamical hair growth in black hole binaries in Einstein-scalar-Gauss-Bonnet gravity
SISSA（的里雅斯特国际高等研究学院）；INFN Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；Dipartimento di Fisica, Sapienza Università di Roma（罗马第一大学物理系）；Instituut voor Theoretische Fysica, KU Leuven（荷鲁芬大学理论物理研究所）；Leuven Gravity Institute, KU Leuven（荷鲁芬大学引力研究所）；Departament d’Astronomia i Astrofísica, Universitat de València（瓦伦西亚大学天文与天体物理学系）；Theoretical Astrophysics, Eberhard Karls University of Tübingen（蒂宾根大学理论天体物理学）；Department of Theoretical Physics, Faculty of Physics, Sofia University（索非亚大学物理学院理论物理系）；Institute of Mathematics and Informatics, Bulgarian Academy of Sciences（保加利亚科学院数学与信息学研究所）
Third-generation (3G) gravitational-wave (GW) detectors will be able to observe binary-black-hole mergers (BBHs) up to redshift of $\sim 30$. This gives unprecedented access to the formation and evolution of BBHs throughout cosmic history. In this paper we consider three sub-populations of BBHs originating from the different evolutionary channels: isolated formation in galactic fields, dynamical formation in globular clusters and mergers of black holes formed from Population III (Pop III) stars at very high redshift. Using input from populations synthesis analyses, we created two months of sim…
Primordial black holes possibly formed in the early universe could provide a significant fraction of the dark matter and would be unique probes of inflation. A smoking gun for their discovery would be the detection of a subsolar mass compact object. We argue that extreme mass-ratio inspirals will be ideal to search for subsolar-mass black holes not only with LISA but also with third-generation ground-based detectors such as Cosmic Explorer and the Einstein Telescope. These sources can provide unparalleled measurements of the mass of the secondary object at subpercent level for primordial black…
The Einstein Telescope (ET), a future third-generation gravitational wave detector will have detection sensitivity for gravitational wave signals down to 1 Hz. This improved low-frequency sensitivity of the ET will allow the observation of low mass binaries for a longer period of time in the detection band before their merger. Because of an improved sensitivity as compared to current and advanced 2G detectors, the detection rate will also be greatly improved. Given the high detection rate of merging compact binaries with the ET, it will be a useful instrument to conduct population studies. In …
Black hole binaries in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理研究所（爱因斯坦研究所））；Institute of Applied Computing & Community Code (IAC3), Universitat de les Illes Balears（巴利阿里群岛大学应用计算与社区代码研究所）；KU Leuven（荷语鲁汶大学）；Leuven Gravity Institute, KU Leuven（荷语鲁汶大学鲁汶引力研究所）；Queen Mary University of London（伦敦大学玛丽女王学院）
We explore the use of the mass spectrum of neutron stars and black holes in gravitational-wave compact binary sources as a cosmological probe. These standard siren sources provide direct measurements of luminosity distance. In addition, features in the mass distribution, such as mass gaps or peaks, will redshift, and thus provide independent constraints on their redshift distribution. We argue that the entire mass spectrum should be utilized to provide cosmological constraints. For example, we find that the mass spectrum of LIGO--Virgo--KAGRA events introduces at least five independent mass ``…
The Einstein Telescope (ET) is the future third generation gravitational wave detector consisting of three independent interferometers arranged in a triangular configuration, with the sensitivity large enough to be able to detect stellar mass black holes even beyond the redshift of 10. In this paper, we analyze the capabilities of ET as a standalone instrument and not part of a network. We show that the analysis of detection of binary coalescences in the three individual interferometers of the ET allow us to weakly constrain the sky location of the source. We present the analysis that leads to…
Equation of motion for relativistic compact binaries with the strong field point particle limit : Formulation, the first post-Newtonian and multipole terms
Third-generation gravitational wave (GW) observatories such as Einstein Telescope (ET) and Cosmic Explorer (CE) will be ideal instruments to probe the structure of neutron stars through the GWs they emit when undergoing binary coalescence. In this work we make predictions about how well ET in particular will enable us to reconstruct the neutron star equation of state through observations of tens of binary neutron star coalescences with signal-to-noise ratios in the hundreds. We restrict ourselves to information that can be extracted from the inspiral, which includes tidal effects and possibly …
Post-Newtonian dynamics of charged compact binaries
International Centre for Theoretical Physics Asia-Pacific, University of Chinese Academy of Sciences（国际理论物理中心亚太区，中国科学院大学）；Taiji Laboratory for GW Universe, University of Chinese Academy of Sciences（引力波宇宙太极实验室，中国科学院大学）；School of Physics and Optoelectronic Engineering, Yangtze University（长江大学物理与光电工程学院）；School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences（中国科学院大学杭州高等研究院基础科学与数学学院）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；School of Physical Science and Technology, Lanzhou University（兰州大学物理科学与技术学院）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）
Spin-induced Quadrupole Moment (SIQM) Test for Eccentric Compact Binaries
Indian Institute of Technology Madras（印度马德拉斯理工学院）；Centre for Strings, Gravitation and Cosmology, Department of Physics, Indian Institute of Technology Madras（印度马德拉斯理工学院物理学院弦、引力和宇宙学中心）
By virtue of their sub-hour orbital periods, ultra-compact X-ray binaries are promising sources for the space-borne gravitational-wave interferometers LISA, Taiji, and TianQin. Some of these systems contain a neutron star primary, whose spin period can be measured directly via pulse timing, or indirectly through rotational modulations of burst phenomena. It is pointed out here that since actively accreting stars, with spin frequencies in the hundreds of Hz, may continuously emit appreciable gravitational waves due to the presence of accretion-built mountains, toroidal magnetic fields, and/or $…
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research（国际理论科学中心，塔塔基础研究所）；CEICO, FZU-Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所FZU-CEICO）
