Inflation in warped geometries

We argue that brane anti-brane inflation in string theory de-Sitter vacua of KachruKallosh-Linde-Trivedi (KKLT) is captured by the dynamics of a D3-brane probe in the local KKLT model constructed in hep-th/0203041. This provides a framework to study in a controllable way corrections to the inflationary slow roll parameter η due to conformal symmetry breaking in a warped geometry throat. We compute the leading correction to η for the inflation in the Klebanov-Tseytlin throat geometry. We find that in certain regime this correction tends to decrease η. Computations in a different regime suggest however that it is unlikely that η ≪ 1 can be achieved with the D3-brane throat inflation.