arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1509.07585astro-ph.COgr-qchep-ph
收藏

用星系巡天探测高阶原始非高斯性

Probing higher-order primordial non-Gaussianity with galaxy surveys

Daisuke Yamauchi, Keitaro Takahashi

摘要:

通过平方公里阵列(SKA)的射电连续星系调查,欧几里德的光度星系调查及其组合,我们预测了未来对原始非高斯性的限制。我们重点研究了局域型高阶非线性参数对参数估计的潜在影响,特别是暴胀相容性不等式的证明。非标准的暴胀模型,如多场模型,引入了大尺度下星系的尺度依赖随机成团,这是对原初密度涨落产生机制的独特探索。Fisher矩阵分析表明,SKA提供的深度和广度的观测更有利于约束$τ_{\rm NL}$,而Euclid由于红移信息对$f_{\rm NL}$有很强的约束力,这表明两者之间的联合分析对于打破非线性参数之间的简并是非常必要的。完整的SKA和Euclid的组合将达到所需的精度水平,以确认即使是$f_{\rm NL}\approx 1.5$和$τ_{\rm NL}\approx 17$的一致性不等式,虽然它仍然是很难的一个单一的调查,以确认它时,$f_{\rm NL}\lesssim 2.7$。

英文摘要:

With a radio continuum galaxy survey by the Square Kilometre Array (SKA), a photometric galaxy survey by Euclid and their combination, we forecast future constraints on primordial non-Gaussianity. We focus on the potential impact of local-type higher-order nonlinear parameters on the parameter estimation and particularly the confirmation of the inflationary consistency inequality. Nonstandard inflationary models, such as multifield models, introduce the scale-dependent stochastic clustering of galaxies on large scales, which is a unique probe of mechanism for generating primordial density fluctuations. Our Fisher matrix analysis indicates that a deep and wide survey provided by SKA is more advantageous to constrain $τ_{\rm NL}$, while Euclid has a strong constraining power for $f_{\rm NL}$ due to the redshift information, suggesting that the joint analysis between them is quite essential to break the degeneracy between the nonlinear parameters. The combination of the full SKA and Euclid will achieve the precision level needed to confirm the consistency inequality even for $f_{\rm NL}\approx 1.5$ and $τ_{\rm NL}\approx 17$, though it is still hard for a single survey to confirm it when $f_{\rm NL}\lesssim 2.7$.

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。

↑