论文标题
非线性状态中的引力波化石：引力波单独的宇宙模拟中的光环潮汐偏置和内在比对
Gravitational wave fossils in nonlinear regime: halo tidal bias and intrinsic alignments from gravitational wave separate universe simulations
论文作者
论文摘要
我们通过利用潮汐单独的宇宙模拟来研究长波长重力波（GWS）对非线性结构形成的影响。基于将长波长GW等效到局部框架中统一的潮汐场的等效性，我们提供了一种将长波长GW纳入潮汐单独的宇宙模拟中的方法，作为有效的各向异性扩张。这种方法使我们能够有效地研究GW对大规模结构的影响。我们从潮汐单独的宇宙模拟的局部功率谱中测量各向异性烙印，该宇宙模拟与GWS相对应，与挤压极限或所谓的GWS的所谓功率谱响应相对应。我们还检测到GWS引起的Halo潮汐偏置，从Halo-MANTER跨功率谱对GWS的响应以及GWS引起的线性形状偏置（或线性比对系数）从Halo Ellipticity的一点点函数引起的线性形状偏差（或线性比对系数）。与标量扰动引起的潮汐场相反，我们发现，GWS时间演化的波数依赖性自然会导致这些偏见依赖于规模依赖性。我们还发现，这种量表依赖性通过标量和张量扰动之间的耦合所引起的二阶密度很好地近似。这强调了结构的形成，尤其是确定光环形状的过程，在时间上是非本地的。我们的发现为预测GW对大规模结构的影响奠定了基础。
We investigate impacts of long-wavelength gravitational waves (GWs) on nonlinear structure formation by utilizing the tidal separate universe simulations. Based on the equivalence of a long-wavelength GW to a uniform tidal field in a local frame, we provide a way to incorporate a long-wavelength GW into the tidal separate universe simulation as an effective anisotropic expansion. This methodology enables us to study effects of GWs on large-scale structure efficiently. We measure the anisotropic imprint in the local power spectrum from the tidal separate universe simulations with GWs, which corresponds to the scalar-scalar-tensor bispectrum in squeezed limit or the so-called power spectrum response to GWs. We also detect the halo tidal bias induced by GWs from the response of the halo-matter cross-power spectrum to GWs, as well as the linear shape bias (or the linear alignment coefficient) induced by GWs from the one-point function of the halo ellipticity. In contrast to the case of the tidal field induced by scalar perturbations, we discover that the wavenumber dependence of the temporal evolution of GWs naturally causes these biases to be scale-dependent. We also find that this scale dependence is well approximated by the second-order density induced by the coupling between scalar and tensor perturbation. This highlights that the structure formation, especially the process to determine the halo shape, is nonlocal in time. Our findings lay the foundation for predicting the impact of GWs on large-scale structure.
