Supergravity and Two-Field Inflation Effects in Right-Handed Sneutrino-Modified D-term Inflation

We extend previous work on the minimal D-term inflation model modified by Right-Handed (RH) sneutrino fields to include additional inflaton-sector SUGRA corrections and two-field inflation effects. We show that SUGRA corrections simultaneously allow ns to be within 3-year WMAP limits and the cosmic string contribution to the CMB power spectrum to be less than 5%. For gauge coupling g ≤ 1, the CMB contribution from cosmic strings is predicted to be at least 1% while the spectral index is predicted to be less than 0.968 for a CMB string contribution less than 5%. Treating the inflaton-RH sneutrino system as a two-field inflation model, we show that the time-dependence of the RH sneutrino field strongly modifies the single-field results for values of RH sneutrino mass mΦ > 0.1H. The running spectral index is α ≈ −0.0002 when mΦ < 0.1H but increases to positive values as mΦ/H increases, with α > 0.008 for mΦ > 1.0H. [email protected], [email protected]