Open inflationary Universe

点击翻译按钮获取中文摘要

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.