INFLATION FROM IIB SUPERSTRINGS WITH FLUXES

We study the conditions needed to have an early epoch of inflationary expansion with a potential coming from type IIB superstring theory with fluxes involving two modulus fields. The phenomenology of this potential is different from the usual hybrid inflation scenario and we analyze the possibility that the system of field equations undergoes a period of inflation in three different regimes with the dynamics modified by a Randall–Sundrum term in the Friedmann equation. We find that the system can produce inflation and, due to the modification of the dynamics, a period of accelerated contraction can follow or precede this inflationary stage, depending on the sign of one of the parameters of the potential. We discuss the viability of this model in a cosmological context.

THE PRIMEVAL STRUCTURE TELESCOPE

The PrimevAl Structure Telescope (PAST), will be used to locate and study the era the of the first luminous objects, the epoch of reionization. The first stars ionized the gas around them producing a pattern of ionization that reflects the large scale density structure present at the time. The PAST array will be used to sense and study this ionization, by mapping the brightness of 21 cm neutral Hydrogen Cosmic Background (HCB) at redshift from 6 to 25. The HCB disappears on ionization, allowing the study of large scale structure and of star formation at this very early epoch.