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arXiv 0706.0981gr-qc
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缓慢膨胀过程中的原始扰动

Primordial Perturbations During a Slow Expansion

Yun-Song Piao

摘要:

最近的研究表明,早期宇宙的缓慢膨胀可能导致原初微扰的产生,而原初微扰是可观测宇宙结构形成的主要原因,这种缓慢膨胀在无限的过去是一种渐近的静态,可以描述为ε \ll-1的演化。但其可行性取决于相变后曲率扰动的常值模式是否能继承相变前的巴氏势增长模式。在本文中,我们把这种慢膨胀现象看作是由多个违反标量场的NEC驱动的。我们计算了相变前熵微扰引起的曲率微扰,发现光谱具有自然的标度不变性,并有轻微的红倾斜。这个结果与慢滚暴胀有一个有趣的相似之处。

英文摘要:

Recently, it has been showed that a slow expansion, which is asymptotically a static state in infinite past and may be described as an evolution with ε\ll -1, of early universe may lead to the generation of primordial perturbation responsible for the structure formation of observable universe. However, its feasibility depends on whether the growing mode of Bardeen potential before phase transition can be inherited by the constant mode of curvature perturbation after phase transition. In this note, we phenomenally regard this slow expansion as that driven by multi NEC violating scalar fields. We calculate the curvature perturbation induced by the entropy perturbation before phase transition, and find that the spectrum is naturally scale invariant with a slight red tilt. The result has an interesting similarity to that of slow roll inflation.

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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