Warp factor and the gravitational wave spectrum

A distinct signature of compact extra dimensions would be a Kaluza-Klein tower gravitational waves. Motivated by this prospect, we compute the corresponding spectrum on warped toroidal background. We evaluate in particular impact warp factor spectrum. To that end, use complete H standard string compactifications, generated D-branes and orientifolds, thus connecting to recent works stringy de Sitter constructions. The problematic region close an orientifold where < 0 leads unphysical tachyonic modes develop tools overcome difficulty lead tachyon-free show, particular, can lower first mass at least 69%.