论文标题
结合星系镜头和偏光Sunyaev-Zel'Dovich效应的新型宇宙学测试
Novel Cosmological Tests from Combining Galaxy Lensing and the Polarized Sunyaev-Zel'dovich Effect
论文作者
论文摘要
极化的Sunyaev-Zel'Dovich（PSZ）效应是通过遥远的游离电子的CMB光子散射来提供的，并在整个可观察的宇宙中产生了CMB四极杆的新型视图。 Galaxy剪切测量星系的形状扭曲，探测其本地环境和中间物质分布。两种可观察的东西都对宇宙学模型产生了有趣的限制。我们在这里问：从他们的组合中可以学到什么？ PSZ剪切横光谱测量了剪切 - 半偏振双光谱，并包含（1）Sachs-Wolfe（SW）效应的贡献，（2）综合的Sachs-Wolfe（ISW）效应和（3）膨胀重力波。由于导致PSZ信号的模式不仅限于地球过去的灯酮，因此低红移横谱可以通过ISW效应对暗能量提供新的限制，而SW信号夫妇在非常不同的时间，但在相似的位置处。这提供了对宇宙同质时间演变的独特探测。我们为剪切，银河系和PSZ自动和跨光谱的所有主要贡献提供表达，并通过Fisher预测评估它们的可检测性。尽管理论上的实用性很高，但跨光谱的检测将具有挑战性：将CMB-S4与Rubin结合起来的ISW贡献的$1.6σ$检测，对于涉及CMB-HD的未来主义实验和较高星系样品密度的未来主义实验，它增加到5.2σ$。对于平均值（均等）张量，我们预计CMB-S4和Rubin的$1σ$限制为$σ（R）= 0.9 $（$ 0.2 $），或更未来主义的设置为$ 0.3 $（0.06 $）。尽管这比单独使用星系剪切的约束（并且对系统敏感）要好得多，但不可能具有竞争力，但可以用作有用的交叉检查。
The polarized Sunyaev-Zel'dovich (pSZ) effect is sourced by the Thomson scattering of CMB photons from distant free electrons and yields a novel view of the CMB quadrupole throughout the observable Universe. Galaxy shear measures the shape distortions of galaxies, probing both their local environment and the intervening matter distribution. Both observables give interesting constraints on the cosmological model; here we ask: what can be learnt from their combination? The pSZ-shear cross-spectrum measures the shear-galaxy-polarization bispectrum and contains contributions from (1) the Sachs-Wolfe (SW) effect, (2) the integrated Sachs-Wolfe (ISW) effect, and (3) inflationary gravitational waves. Since the modes contributing to the pSZ signal are not restricted to the Earth's past lightcone, the low-redshift cross-spectra could provide a novel constraint on dark energy via the ISW effect, whilst the SW signal couples scalar modes at very different times but at similar positions; this provides a unique probe of the Universe's homogeneous time evolution. We give expressions for all major contributions to the shear, galaxy, and pSZ auto- and cross-spectra, and evaluate their detectability via Fisher forecasts. Despite significant theoretical utility, the cross-spectra will be challenging to detect: combining CMB-S4 with Rubin yields a $1.6σ$ detection of the ISW contribution, which increases to $5.2σ$ for a futuristic experiment involving CMB-HD and a higher galaxy sample density. For parity-even (parity-odd) tensors, we predict a $1σ$ limit of $σ(r) = 0.9$ ($0.2$) for CMB-S4 and Rubin, or $0.3$ ($0.06$) for the more futuristic setup. Whilst this is significantly better than the constraints from galaxy shear alone (and less sensitive to systematics), it is unlikely to be competitive, but may serve as a useful cross-check.
