论文标题
随机重力波背景的波动极限
Wave-optics limit of the stochastic gravitational wave background
论文作者
论文摘要
随机引力波背景（SGWB）是宇宙学信息的丰富资源，既编码在其源统计和传播效应引起的各向异性中。我们提供了理论上的描述，而无需使用依赖几何光学限制的理论工具。我们的形式主义基于所谓的{\ it经典物质近似}，并且能够捕获波播效应，例如干扰和衍射。我们表明，在调节张力张力方面的基础上，引力波与沿视线的宇宙结构之间的相互作用产生了可观察到的标量和矢量极化模式。我们构建了描述SGWB统计数据的两个点相关函数，并引入了其所有组件的强度和重力Stokes参数。对于一个非极化，高斯和统计上均匀的SGWB的情况，我们表明与物质的相互作用调节了其强度，并且不会如预期的那样在左和右 - 螺旋张量和矢量模式之间产生净差异。我们证明，为了产生$ q_t $ - 和$ u_t $ - 张量极化模式，背景必须具有十六进制的各向异性，而quandrupole各向异性则可以采购vector $ q_v $ - 和$ q_v $ - 和$ u_v $ - Stokes参数。
The stochastic gravitational wave background (SGWB) is a rich resource of cosmological information, encoded both in its source statistics and anisotropies induced by propagation effects. We provide a theoretical description of it, without employing theoretical tools which rely on the geometric optics limit. Our formalism is based on the so-called {\it classical matter approximation} and it is able to capture wave-optics effects, such as interference and diffraction. We show that the interaction between the gravitational waves and the cosmic structures along the line-of-sight produce observable scalar and vector polarization modes, on top of modulating the tensorial ones. We build the two point correlation function describing the statistics of the SGWB, and introduce the intensity and gravitational Stokes parameters for all its components. In the case of an unpolarized, Gaussian and statistically homogeneous SGWB, we show that the interaction with matter modulates its intensity and does not generate a net difference between left- and right- helicity tensor and vector modes, as expected. We demonstrate that, in order to produce $Q_T$- and $U_T$- tensor polarization modes the background must posses an hexadecapole anisotropy, while a quandrupole anisotropy can source the vector $Q_V$- and $U_V$- Stokes parameters.
