论文标题
Nancy Grace Roman Space望远镜和Rubin天文台遗产时空的跨双光谱限制对时间和时间的鲁宾天文台传统调查
Cross-bispectra Constraints on Modified Gravity Theories from Nancy Grace Roman Space Telescope and Rubin Observatory Legacy Survey of Space and Time
论文作者
论文摘要
即将进行大规模结构调查的主要目标是限制黑暗能量和修改的重力理论。特别是，星系聚类和重力透镜收敛是对一般相对性修饰敏感的探针。尽管这些调查的标准分析通常包括功率谱或2点相关函数，但众所周知，双光谱包含更多信息，并且与功率谱结合使用时可以对参数提供改进的约束。但是，到目前为止，Bispectra的使用已限制为一个探针，例如镜头收敛双光谱或星系双光谱。在本文中，我们扩展了形式主义，以探索不同探针之间跨双光谱的力量，并利用其打破参数脱生并改善约束的能力。我们将其研究在镜头收敛和星系密度自动和跨双镜的测试案例上，该测试案例是特定的horndeski sub-class of Horndeski理论，该理论通过$ c_m $和$ c_b $参数为参数。使用2000度$^2 $对Nancy Grace Roman Space望远镜的概念调查，并从Rubin天文台的时空调查中重叠的光度法，我们发现联合功率谱和Bispectra分析，三个红移箱，$ l _ {\ rm max} = 1000 $ $ l _ {\ rm max} 0.3 $，两倍的$ \ sim $ 1.2 $ 1.2都比功率光谱结果好；如果$ l _ {\ rm max} = 3000 $，则将进一步提高到$σ_{C_M} = 0.7 $和$σ_{C_B} = 0.2 $。此外，我们发现，使用不同断层扫描中的两个探针之间的所有可能的跨双光谱，在自动双光谱结果上改善了1.3倍的倍数，$σ_{c_m} $，1.1 in $σ_{c_b} $ 1.1 in $σ_{c_b} $和1.3 in $σ_{ω__m} $。我们预计，在探针之间使用跨双光谱的好处可能适用于其他科学案例和调查。
One major goal of upcoming large-scale-structure surveys is to constrain dark energy and modified gravity theories. In particular, galaxy clustering and gravitational lensing convergence are probes sensitive to modifications of general relativity. While the standard analysis for these surveys typically includes power spectra or 2-point correlation functions, it is known that the bispectrum contains more information, and could offer improved constraints on parameters when combined with the power spectra. However, the use of bispectra has been limited so far to one single probe, e.g. the lensing convergence bispectrum or the galaxy bispectrum. In this paper, we extend the formalism to explore the power of cross-bispectra between different probes, and exploit their ability to break parameter degeneracies and improve constraints. We study this on a test case of lensing convergence and galaxy density auto- and cross-bispectra, for a particular sub-class of Horndeski theories parametrized by $c_M$ and $c_B$. Using the 2000 deg$^2$ notional survey of the Nancy Grace Roman Space Telescope with overlapping photometry from the Rubin Observatory Legacy Survey of Space and Time, we find that a joint power spectra and bispectra analysis with three redshift bins at $l_{\rm max} = 1000$ yields $σ_{c_M} = 1.0$ and $σ_{c_B} = 0.3$, both a factor of $\sim$1.2 better than the power spectra results; this would be further improved to $σ_{c_M} = 0.7$ and $σ_{c_B} = 0.2$ if $l_{\rm max} = 3000$ is taken. Furthermore, we find that using all possible cross-bispectra between the two probes in different tomographic bins improves upon auto-bispectra results by a factor of 1.3 in $σ_{c_M}$, 1.1 in $σ_{c_B}$ and 1.3 in $σ_{Ω_m}$. We expect that similar benefits of using cross-bispectra between probes could apply to other science cases and surveys.
