Cosmological density perturbations from perturbed couplings
Cosmological density perturbations from perturbed couplings
复制标题
扰动耦合引起的宇宙密度扰动
DOI：
10.1103/physrevd.68.083510
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发表时间：
2003
影响因子：
5
通讯作者：
S. Tsujikawa
中科院分区：
文献类型：
--
作者：
S. Tsujikawa
研究了轻标量场扰动暴胀衰变速率时产生的密度微扰。通过显式求解两标量场和辐射系统的微扰方程，我们证明了即使在低能量标量膨胀中，通过将涨落转化为绝热密度扰动，也可以得到由观测设定的振幅的标量微扰的近标度不变谱。我们证明了谱依赖于膨胀子的平均衰减率&取决于膨胀子的涨落。然后，我们将这一新机制应用于弦宇宙论&广义爱因斯坦理论，并讨论了尺度不变光谱的条件。
The density perturbations generated when the inflaton decay rate is perturbed by a light scalar field $\chi$ are studied. By explicitly solving the perturbation equations for the system of two scalar fields and radiation, we show that even in low energy-scale inflation nearly scale-invariant spectra of scalar perturbations with an amplitude set by observations are obtained through the conversion of $\chi$ fluctuations into adiabatic density perturbations. We demonstrate that the spectra depend on the average decay rate of the inflaton & on the inflaton fluctuations. We then apply this new mechanism to string cosmologies & generalized Einstein theories and discuss the conditions under which scale-invariant spectra are possible.