arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 0709.1940gr-qc
收藏

随机引力的宇宙学扰动

Cosmological perturbations from stochastic gravity

Albert Roura, Enric Verdaguer

备注：
29 pages, REVTeX; minor changes, additional appendix with an alternative proof of the equivalence between stochastic and quantum correlation functions as well as an exact argument showing that the correlation function of curvature perturbations remains constant in time for superhorizon modes, which clarifies a recent claim in arXiv:0710.5342v1
发表信息：
Phys.Rev.D78:064010,2008
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

在由暴胀子场驱动的暴胀宇宙学模型中，导致大尺度结构形成的原初不均匀性的起源是暴胀子场的量子涨落。这些通常是用标准的宇宙学扰动理论计算的，在这个理论中引力场和暴胀子场都是线性扰动和量子化的。然后计算了原始度规涨落的关联函数及其功率谱。在这里，我们介绍了一个替代的程序来计算的度量相关的基础上出现在随机半经典引力的框架下的爱因斯坦-朗之万方程。我们表明，关联函数的度量扰动，遵循爱因斯坦-朗之万形式主义与通常的量子化程序时得到的标量场扰动线性化。这种方法被明确地应用到一个简单的模型的混沌膨胀组成的罗伯逊-沃克背景，经历了准德西特膨胀，最低限度地耦合到一个自由的大质量量子标量场。然而，基于爱因斯坦-朗之万方程的技术可以自然地处理标量场的扰动，甚至超出线性近似，这实际上是在不受暴胀子场驱动的暴胀模型中所需要的，例如Starobinsky的迹线异常驱动的暴胀，或者在通常的暴胀子驱动模型中计算由于非线性量子效应引起的修正。

英文摘要：

In inflationary cosmological models driven by an inflaton field the origin of the primordial inhomogeneities which are responsible for large scale structure formation are the quantum fluctuations of the inflaton field. These are usually computed using the standard theory of cosmological perturbations, where both the gravitational and the inflaton fields are linearly perturbed and quantized. The correlation functions for the primordial metric fluctuations and their power spectrum are then computed. Here we introduce an alternative procedure for computing the metric correlations based on the Einstein-Langevin equation which emerges in the framework of stochastic semiclassical gravity. We show that the correlation functions for the metric perturbations that follow from the Einstein-Langevin formalism coincide with those obtained with the usual quantization procedures when the scalar field perturbations are linearized. This method is explicitly applied to a simple model of chaotic inflation consisting of a Robertson-Walker background, which undergoes a quasi-de-Sitter expansion, minimally coupled to a free massive quantum scalar field. The technique based on the Einstein-Langevin equation can, however, deal naturally with the perturbations of the scalar field even beyond the linear approximation, as is actually required in inflationary models which are not driven by an inflaton field such as Starobinsky's trace-anomaly driven inflation or when calculating corrections due to non-linear quantum effects in the usual inflaton driven 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。

↑