Inflationary RSII model with a matter in the bulk and exponential potential of tachyon field

Abstract

In this paper, we study a tachyon cosmological model based on the dynamics of a 3-brane in the second Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter in the bulk changes the warp factor which leads to the modification of inflationary dynamics. The additional brane behaves effectively as a tachyon. We calculate numerically observation parameters of inflation: the scalar spectral index (ns) and the tensor-to-scalar ratio (r) for the exponential potential of the tachyon field.