Supergravity corrections due to the energy density of a right-handed sneutrino can generate a negative mass squared for the inflaton, flattening the inflaton potential and reducing the spectral index and inflaton energy density. For the case of D-term hybrid inflation, we show that the spectral index can be lowered from the conventional value n=0.98 to a value within the range favored by the latest WMAP analysis, n=0.951-0.019+0.015. The modified energy density is consistent with nonobservation of cosmic strings in the CMB if n<0.946. The WMAP lower bound on the spectral index implies that the D-term cosmic string contribution may be very close present CMB limits, contributing at least 5% to the CMB multipoles.
One of the first papers to discuss the implications for inflation models of the latest 3-year WMAP CMB observations. It has generated new research on SUSY inflation models and cosmic strings. Basis of a new RTN collaboration with the Helsinki Institute of Physics (Ferrantelli and Enqvist). 14 citations (SPIRES). RAE_import_type : Journal article RAE_uoa_type : Physics