The open inflationary scenario is attracting a renewed interest in the context of string landscape. Since there are a large number of metastable de Sitter vacua in string landscape, tunneling transitions to lower metastable vacua through the bubble nucleation occur quite naturally, which leads to a natural realization of open inflation. We argued that the effect of the small deviation of the density parameter on the large angle CMB anisotropies may be significant for tensor-type perturbation in open inflation scenario. We found that the square amplitude for tensor-perturbation is determined not by the Hubble of the false vacuum directly but by that of the true vacuum even for sufficiently steep slope. Also we found that the tracking behavior can appear when one can choose the exponential-type potential with tuned parameters.
展开▼
