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arXiv 0911.2601astro-ph.CO
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关于暗能量的测定

On the determination of dark energy

Chris Clarkson

摘要:

我考虑了我们在试图理解暗能量时所面临的一些问题。未知的暗能量状态方程中的巨大波动可能隐藏在距离数据中,因此我认为,如果宇宙学常数是错误的,那么与模型无关的测试是有价值的。这些可以被构造来消除宇宙学参数的简并。引力效应可以发挥重要作用。即使是很小的不均匀性也会影响我们对暗能量的判断。我讨论了如何平均化问题混淆了我们潜在的理解暗能量,考虑从密度扰动的逆反应的和谐模型中的二阶:这种效果导致至少10%的减速参数的动态值增加,并可能显着更高。大哈勃尺度的不均匀性还没有被详细研究过,可以想象它可能是宇宙加速的原因。我讨论了哈勃补丁中违背哥白尼原理的空洞模型,并描述了我们如何可能排除这些模型。

英文摘要:

I consider some of the issues we face in trying to understand dark energy. Huge fluctuations in the unknown dark energy equation of state can be hidden in distance data, so I argue that model-independent tests which signal if the cosmological constant is wrong are valuable. These can be constructed to remove degeneracies with the cosmological parameters. Gravitational effects can play an important role. Even small inhomogeneity clouds our ability to say something definite about dark energy. I discuss how the averaging problem confuses our potential understanding of dark energy by considering the backreaction from density perturbations to second-order in the concordance model: this effect leads to at least a 10% increase in the dynamical value of the deceleration parameter, and could be significantly higher. Large Hubble-scale inhomogeneity has not been investigated in detail, and could conceivably be the cause of apparent cosmic acceleration. I discuss void models which defy the Copernican principle in our Hubble patch, and describe how we can potentially rule out these models.

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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