Multi-brane Inflation in String Theory – Amjad Ashoorioon

Date: Tue. January 27th, 2009, 11:30 am-12:30 pm
Location: Rockefeller 221

I will talk about two inflationary scenarios in which the cooperative behavior of multiple branes give rise to inflation. In the first one, which we call cascade inflation, assisted inflation is realized in heterotic M-theory and by non-perturbative interactions of N M5-branes. The features in the inflaton potential are generated whenever two M5-branes collide with the boundaries. The derived small-scale power suppression could serves as a possible explanation for the dearth of observed dwarf galaxies in the Milky Way halo. In the second one, the transverse dimension of coincident D3-branes, which are N-dimensional matrices, result in inflation. We discuss how various scenarios such as chaotic, hilltop and inflection-point inflations could be constructed with this setup. Due to matrix nature of inflaton fields, more scalar fields can get involved which can result in the production of isocurvature perturbations, beside the adiabatic ones.