2 research outputs found
An Inflationary Scenario in Intersecting Brane Models
We propose a new scenario for D-term inflation which appears quite
straightforwardly in the open string sector of intersecting brane models. We
take the inflaton to be a chiral field in a bifundamental representation of the
hidden sector and we argue that a sufficiently flat potential can be brane
engineered. This type of model generically predicts a near gaussian red
spectrum with negligible tensor modes. We note that this model can very
naturally generate a baryon asymmetry at the end of inflation via the recently
proposed hidden sector baryogenesis mechanism. We also discuss the possibility
that Majorana masses for the neutrinos can be simultaneously generated by the
tachyon condensation which ends inflation. Our proposed scenario is viable for
both high and low scale supersymmetry breaking.Comment: 30 pages, 2 figures; v2 references and comments adde
Conditions for large non-Gaussianity in two-field slow-roll inflation
We study the level of primordial non-Gaussianity in slow-roll two-field
inflation. Using an analytic formula for the nonlinear parameter f_nl in the
case of a sum or product separable potential, we find that it is possible to
generate significant non-Gaussianity even during slow-roll inflation with
Gaussian perturbations at Hubble exit. In this paper we give the general
conditions to obtain large non-Gaussianity and calculate the level of
fine-tuning required to obtain this. We present explicit models in which the
non-Gaussianity at the end of inflation can exceed the current observational
bound of |f_nl|<100.Comment: 16 pages, 6 figures, 1 table, v2: typos corrected and references
added, matches version accepted by JCA