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arXiv 1402.2161astro-ph.CO
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用伽马射线暴探测高红移处的宇宙不透明度

Probing cosmic opacity at high redshifts with gamma-ray bursts

R. F. L. Holanda, V. C. Busti

摘要:

用标准烛光探测宇宙在高红移处的演化是区分暗能量模型的一种有力方法,现在的一个悬而未决的问题是这个分量是恒定的还是随时间演化的。在这种分析中,一个可能的模糊性来源来自宇宙的不透明性,它可以模仿暗能量的行为。然而,大多数宇宙不透明度的测试都局限于红移范围$z<2$。本文利用伽马射线暴(GRB)的光度距离,{在Amati关系成立的条件下},以及最新的$H(z)$数据,确定了平坦$Λ$ CDM模型在高红移($z>2$)下宇宙不透明度的约束条件。一个可能的退化的结果与所采用的宇宙学模型也被调查考虑一个平坦的XCDM模型。宇宙不透明度在红移范围$0<z<2$的限制更新与Ia型超新星(SNe Ia)从联盟2.1的样本,在那里我们添加了最遥远的($z=1.713$)光谱证实的SNe Ia。通过分析,我们发现Ia超新星和伽玛暴样品在$1σ$水平上都与透明宇宙相容,并且结果与暗能量状态方程参数$w$无关.

英文摘要:

Probing the evolution of the universe at high redshifts with standard candles is a powerful way to discriminate dark energy models, where an open question nowadays is whether this component is constant or evolves with time. One possible source of ambiguity in this kind of analyses comes from cosmic opacity, which can mimick a dark enery behaviour. However, most tests of cosmic opacity have been restricted to the redshift range $z<2$. In this work, by using luminosity distances of gamma-ray bursts (GRBs), {given the validity of the Amati relation}, and the latest $H(z)$ data we determine constraints on the cosmic opacity at high redshifts ($z>2$) for a flat $Λ$CDM model. A possible degenerescence of the results with the adopted cosmological model is also investigated by considering a flat XCDM model. The limits on cosmic opacity in the redshift range $0<z<2$ are updated with type Ia supernovae (SNe Ia) from the Union2.1 sample, where we added the most distant ($z=1.713$) spectroscopically confirmed SNe Ia. From the analyses performed, we find that both SNe Ia and GRBs samples are compatible with a transparent universe at $1σ$ level and the results are independent of the dark energy equation of state parameter $w$.

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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