标题： 引力波通过非均匀背景传播时的粘性衰减 显示英文标题

标题： Viscous attenuation of gravitational waves propagating through an inhomogeneous background

摘要： 我们考虑在存在物质分布不均匀性的晚期宇宙中引力波的传播，并且我们也考虑宇宙流体是粘滞的。 在本工作中，我们研究了物质分布不均匀性和宇宙流体粘滞性对与引力波源相关的观测量的累积效应。 采用Buchert的平均化程序，在回反应框架中，我们考虑了一个时空模型，在该模型中物质在空间中不均匀分布。 使用修改后的红移与距离关系，通过在该模型背景下的平均化过程，我们研究了不同模型参数组合下观测到的引力波振幅的红移相关部分的变化，同时考虑由于宇宙流体粘滞性导致的引力波振幅的衰减。 然后，我们研究了由于考虑粘滞衰减而导致的观测到的引力波振幅的红移相关部分变化的差异。 我们表明，在我们的分析中包含粘滞衰减后会出现显著偏差，这取决于所选粘滞系数的值。 我们的结果表明，在非均匀宇宙模型中，粘滞性的影响对引力波紧凑双星源参数的精确测量具有重要意义。 显示英文摘要

摘要： We consider the propagation of gravitational waves in the late-time Universe in the presence of matter distribution inhomogeneities, and we also consider the cosmic fluid to be viscous. In this work, we investigate the cumulative effect of inhomogeneities and viscosity of the cosmic-fluid on the observables associated with the sources of the gravitational waves. Employing Buchert's averaging procedure in the backreaction framework, we consider a model of spacetime in which matter is distributed in-homogeneously across space. Using the modified redshift versus distance relation, through the averaging process in the context of the model, we study the variation of the redshift-dependent part of the observed gravitational wave amplitude for different combinations of our model parameters while simultaneously considering damping of the gravitational wave amplitude due to viscosity of the cosmic-fluid. Then, we investigate the differences occurring in the variation of the redshift-dependent part of the observed gravitational wave amplitude due to consideration of viscous attenuation. We show that there are significant deviations after the inclusion of viscous attenuation in our analysis, depending on the chosen value of the coefficient of viscosity. Our result signifies the importance of the effect of viscosity, within the model of an inhomogeneous Universe, on precision measurements of parameters of compact-binary sources of gravitational waves.