Open inflationary Universe

提出了一种开放膨胀宇宙(单泡开放膨胀)的设想，阐明了一种新的微扰模(超曲率模)与引力波模式之间的关系，提出了一种计算开放膨胀的单分量标量场模型中微扰的方法，并推导了一组解耦的标量模和张量模的规范不变量方程。特别地，我们阐明了张量微扰谱的一般特征，进一步阐明了一类可以成功实现开放膨胀的模型，并研究了微扰谱的特征。结果发现：1.相对于标准暴涨情形，标量谱在长波长端的振幅受到抑制；2.张量谱的长波长端得到增强.3.由此得到的CMB各向异性谱在大角度尺度上保持标度不变.4.对于密度微扰，该谱在接近星系尺度的尺度上有一个Milde峰.这些特征可以在不久的将来通过观测得到验证.

We proposed a scenario of open inflationary universe (one-bubble open inflation), and clarified the relation between a new type of perturbation modes (supercurvature modes) and gravitational wave modes.Then we developed a method to evaluate the perturbations in the single-component scalar field model of open inflation and derived a set of decoupled gauge-invariant equations for the scalar modes and tensor modes. In particular, we clarified the general feature of the tensor perturbation spectrum.Further, we clarified a class of models in which open inflation can be successfully implemented, and investigated the features of perturbation spectra. As a result, we found1.The amplitude of scalar spectrum is suppressed in the long wavelength side relative to the standard scenario of inflation.2.On the other hand, the long wavelength side of tensor spectrum is enhanced.3.Hence the resulting CMB anisotropy spectrum on large angular scales remains scale-invariant.4.As for the density perturbation, the spectrum has a milde peak at scale close to the galaxy scale.These features can be tested observationally in the near future.