2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197256The first year Wilkinson Microwave Anisotropy Probe data favors primordial adiabatic fluctuation with a running spectral index with $\ns >1$ on a large scale and $\ns <1$ on a smaller scale. The model building of inflation that predicts perturbations with such a spectrum is a challenge, because most models predict fluctuations with either $\ns >1$ (hybrid inflation) or $\ns <1$ (new, chaotic, or topological inflation). We give a sensible particle physics model in supergravity that accommodates the desired running of the spectral index using double inflation.13 pages, 3 figures, to appear in Phys. Rev. DHigh Energy Physics - PhenomenologyAstrophysicstext