Braneworld inflation

Abstract

We discuss various realizations of the four dimensional braneworld inflation in warped geometries of string theory. In all models the inflaton field is represented by a Dp probe brane scalar specifying its position in the warped throat of the compactification manifold. We study existing inflationary throat local geometries, and construct a new example. The inflationary brane is either a D3- or a D5-brane of type IIB string theory. In the latter case the inflationary brane is wrapping a two-cycle of the compactification manifold. We discuss some phenomenological aspects of the model where slow-roll conditions are under computational control.Comment: 31 pages + 6 figures, v2: published PRD versio

Braneworld nonminimal inflation with induced gravity

“…This may help to reduce at least part of lacuna of standard scenario. We note also that as has been shown in [11], inflation in warped de Sitter string theory geometries bypasses the difficulties of computing corrections to η slow-roll parameter relative to the effective four dimensional perspective.…”

“…Note that these ansatz are chosen by taking into account the inflationary nature of the solutions for scale factor and a decreasing nature of the scalar field. Applying these ansatz to equation (11) and performing our numerical analysis for quadratic and quartic potentials with ν = 10, a 0 = ϕ 0 = 1 and ϑ = 1, we find for n s the results that are shown in the left panel of figure 11. These results are more generic than the case that we set the Ricci scalar to be a constant due to constancy of H in inflation era.…”

“…Braneworld scenarios open new windows to address at least part of these difficulties [10,11]. One of the various braneworld scenarios, is the model proposed by Dvali, Gabadadze and Porrati (DGP).…”

D‐branes in Standard Model building, gravity and cosmology

“…They have to do with additional couplings on the D-branes that might destroy inflations. There is active research currently on this realization of inflation, [309]- [324], but it seems that the last word has not yet been said.…”

Stringy effects during inflation and reheating

“…Their supergravity duals are weakly curved everywhere and have been used to study the motion of branes during inflation [190,191], so we might expect that these geometries could describe the SM throat during inflation. A central observation in these constructions is that AdS 5 admits a parametrization where the radial slices have a dS 4 geometry [192].…”