arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1801.06342astro-ph.CO
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用亏格振幅估算宇宙学参数--应用于模拟星系表

Cosmological Parameter Estimation Using the Genus Amplitude - Application to Mock Galaxy Catalogs

Stephen Appleby, Changbom Park, Sungwook E. Hong, Juhan Kim

摘要:

研究了二维切片中物质密度场的拓扑结构,并考虑了如何利用亏格的振幅$A$进行宇宙学参数估计。利用最新的Horizon Run 4模拟数据,我们计算了由光锥模拟星系表构造的平滑密度场的亏格。通过考虑其红移演化和星等,可以从属的振幅中提取信息。本征振幅随红移的恒定性可以作为一个标准布居,从中我们导出了对暗能量$w_{\rm de}$状态方程的约束--通过在$z \sim 0.1$和$z \sim 1$处测量$A$,我们可以对$w_{\rm de}$放置一个顺序$Δw_{\rm de} \sim {\cal O}(15\%)$约束。通过将$A$与其高斯期望值进行比较,我们可以潜在地导出对物质密度$ΔΩ_{\rm mat} \sim 0.01$的附加严格约束。我们讨论了与这两个测量相关的污染的主要来源-红移空间失真和散粒噪声。通过对星系偏差的精确了解,我们可以成功地消除红移空间畸变的影响,并通过适当的大尺度平滑$R_{\rm G} \ge 15 {\rm Mpc}/h$来抑制散粒噪声和非线性引力演化的综合影响。没有知识的偏见,我们讨论如何联合测量的二维和三维属可以用来约束生长因子$β= f/b$。该方法可以应用于最佳的红移片的星系分布产生的下降技术。

英文摘要:

We study the topology of the matter density field in two dimensional slices, and consider how we can use the amplitude $A$ of the genus for cosmological parameter estimation. Using the latest Horizon Run 4 simulation data, we calculate the genus of the smoothed density field constructed from lightcone mock galaxy catalogs. Information can be extracted from the amplitude of the genus by considering both its redshift evolution and magnitude. The constancy of the genus amplitude with redshift can be used as a standard population, from which we derive constraints on the equation of state of dark energy $w_{\rm de}$ - by measuring $A$ at $z \sim 0.1$ and $z \sim 1$, we can place an order $Δw_{\rm de} \sim {\cal O}(15\%)$ constraint on $w_{\rm de}$. By comparing $A$ to its Gaussian expectation value we can potentially derive an additional stringent constraint on the matter density $ΔΩ_{\rm mat} \sim 0.01$. We discuss the primary sources of contamination associated with the two measurements - redshift space distortion and shot noise. With accurate knowledge of galaxy bias, we can successfully remove the effect of redshift space distortion, and the combined effect of shot noise and non-linear gravitational evolution is suppressed by smoothing over suitably large scales $R_{\rm G} \ge 15 {\rm Mpc}/h$. Without knowledge of the bias, we discuss how joint measurements of the two and three dimensional genus can be used to constrain the growth factor $β= f/b$. The method can be applied optimally to redshift slices of a galaxy distribution generated using the drop-off technique.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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