Numerical Study of Inhomogeneous Pre-Big-Bang Inflationary Cosmology

We study numerically the inhomogeneous pre-big-bang inflation in a spherically symmetric space-time. We find that a large initial inhomogeneity suppresses the onset of the pre-big-bang inflation. We also find that even if the pre-big-bang inflationary stage is realized, the initial inhomogeneities are not homogenized. Namely, during the pre-big-bang inflation “hairs”(irregularities) do not fall, in sharp contrast to the usual (potential energy dominated) inflation where initial inhomogeneity and anisotropy are damped and thus the resulting universe is less sensitive to initial conditions. PACS numbers: 98.80.Hw, 04.25.Dm, 04.50.+h, 98.80.Cq Typeset using REVTEX ∗Electronic address: [email protected], JSPS research fellow.