Sigma 8 Plus Smooth Corner 8" High x 18" Deep x 8" Long Platinum shown: View Colors

The sigma-8 tension (aka S8 tension or similar) is a contradiction between Lambda-CDM model parameter-determinations based on different kinds of observation data. Among the different kinds of data producing conflicts is that of the cosmic microwave background (CMB) versus that of observed nearby galaxy clusters (i.e., galaxy clusters in their ...

2020年9月21日 · 宇宙学家通过CMB来计算早期宇宙Sigma-8的值，接着通过ΛCDM，他们可以推算出今天Sigma-8的值。这一方法给出的值为0.81，而通过宇宙切变得到的数值为0.76。 四. 之所以会出现这一差异有几种可能性，或许是因为在计算中隐藏着统计误差，又或许是因为ΛCDM出了问 …

天文学家利用覆盖了大约350平方度天区的综合数据，估计出了sigma-8的数值。 然而问题在于，这个数值与根据普朗克卫星对 宇宙微波背景 （CMB）的观测值计算的sigma-8值存在差异。 CMB是宇宙中最早的可观测光，在大爆炸后约38万年发出。

2022年9月13日 · Abstract page for arXiv paper 2209.06217: The Sigma-8 Tension is a Drag Measurements of weak gravitational lensing at low redshifts ($z\lesssim 0.5-1$), quantified by the parameter $S_8$, favor weaker matter clustering than …

2023年6月15日 · Measurements of weak gravitational lensing at low redshifts (z ≲ 0.5 – 1), quantified by the parameter S 8, favor weaker matter clustering than that expected from the standard Λ cold dark matter (Λ CDM) cosmological model with the parameters determined by cosmic microwave background (CMB) measurements.

Sigma8 is a parameter that represents the amplitude of matter density fluctuations on large scales in the universe, as estimated by weak lensing surveys. You might find these chapters and articles relevant to this topic. Henk Hoekstra, ... Michael D Gladders.

2024年5月17日 · Sigma 8-16/4.5-5.6 DC HSM是适马数码相机专用镜头中首款实现8mm的超广角镜头。 该镜头采用了4片全新的光学镜片FLD("F"Low Dispersion)，而这种FLD镜片拥有极低折射率以及极低的色散表现，据适马介绍，这种FLD（人工萤石）镜片的效果等同于萤石镜片，所以镜头 …

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2016年1月20日 · [itex]\sigma_8[/itex] is the current amplitude of the matter power spectrum on that scale (as inferred by linear cosmological evolution). This parameter basically encodes information about how much large-scale structure has formed.