Einstein Telescope (ET) is a project of third generation gravitational wave (GW) detector with a planned sensitivity 10 times better than current detectors such as Advanced LIGO and Advanced Virgo. The high rate of GW signals expected in the data will pose several data analysis challenges, like the ability to disentangle overlapping signals or the need to dimension the computational resources required to treat all the candidate events. We explore the behaviour and the performances of a data analysis pipeline designed to search for unmodelled GW signals with duration 1 to 1000 s on a mock dataset that consists of 1 month of data following ET design sensitivity on top of which is added a realistic distribution of compact binary coalescence (CBC) signals. Unmodelled searches are intrinsically less sensitive to CBC signals than template-based searches, but are computationally cheaper and more robust to uncertainties in the waveforms. This search recovers 38% of the total number of injected binary black hole (BBH) signals, including 89% of the systems with a total mass above 100 solar masses, as well as the majority of binary neutron star (BNS) signals closer than 850 Mpc (z = 0.17). It is also able to estimate the chirp mass of the recovered BNS with an average precision of 1.3%. Therefore, we show that this unmodelled search is able to detect a substantial amount of CBC events at a relatively low computational cost, which makes it interesting for low latency analyses and independent validation of detections made by matched filtering pipelines. We also find that the presence of many CBC signals only marginally impacts the sensitivity of the search to other kinds of unmodelled long duration transient signals, by 3% in average.
Minimally-modeled search of higher multipole gravitational-wave radiation in compact binary coalescence
随着高级LIGO和高级Virgo干涉仪的灵敏度不断提高，很快将加入KAGRA干涉仪的行列，它们探测到的引力波数量越来越多，除了占主导地位的$(2, 2)$多极之外，还存在大量的更高多极。这些更高的多极子可以用不同的方法检测，例如最小模型化的突发搜索方法，在这里，我们讨论了一种基于相干WaveBurst流水线（cWB）的方法。在inspiral阶段的较高的多极产生啁啾的瞬时频率是一个多个占主导地位的（2，2）多极，在这里，我们描述如何cWB可以用来检测这些频谱特征。搜索在时间-频率表示的合适区域内执行;它们的形状通过优化接收器操作特性来确定。这种新方法已在GW 190814发现论文（Astrophys. J. Lett. 896 L44），非常快速和灵活。在这里，我们详细描述了用于检测GW 190814中的（3，3）多极子以及在螺旋阶段搜索其他更高多极子的过程，并将其应用于另一个显示更高多极子的事件GW 190412，复制用不同方法获得的结果。这里描述的过程可以用于快速分析更高的多极子，并支持基于模型的贝叶斯参数估计所获得的结果
Systematic errors in measuring parameters of non-spinning compact binary coalescences with post-Newtonian templates
我们研究的天体物理影响的重力波形的不准确和不完整的建模从紧凑的二元聚结（CBCs）。我们这样做的匹配滤波的完整的吸气合并振铃（IMR）信号与银行的吸气相位模板建模后的3.5后牛顿泰勒T1近似。选择模板的基本原理有三个方面：（1）现象学信号的螺旋相位，这是完整IMR信号的一个例子，在相同的泰勒T1近似上建模。(2)在低质量的限制，合并和衰荡阶段的持续时间比inspiral阶段短得多，误差应该趋于消失的小值，因此，提供了一个重要的检查我们的模拟数值方面。(3)由于双星黑洞（BBH）的信号还不知道质量比超过10，因为来自涉及中子星的CBCs的信号受到其状态方程知识的不确定性的影响，螺旋模板仍然在使用中搜索这些信号。从我们的数值模拟的结果进行了比较与分析计算的系统误差使用的Fisher矩阵的模板参数空间。我们发现，即使对于组分质量为m1 = 13 M \odot和m2 = 20 M \odot的双黑洞，信噪比（SNR）的损失也可以高达60%.此外，同一对的估计总质量可能会偏离20%。这两种情况对于一些更高质量的组合来说都更糟。甚至对称质量比η的估计在这个例子中也有近20%的误差，并且在这里研究的质量范围内可能比50%更差。这些误差显著地支配它们的统计对应物（在标称SNR为10时）。然而，可以通过允许具有非物理值η的模板来减轻SNR的损失。
Unraveling information about supranuclear-dense matter from the complete binary neutron star coalescence process using future gravitational-wave detector networks
PINNGraPE: Physics Informed Neural Network for Gravitational wave Parameter Estimation
INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；INFN Sezione di Ferrara（意大利国家核物理研究所费拉拉分部）；University of Houston（休斯顿大学）；Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文学中心）
