Abstract :
Explaining cosmic inflation by the effective dynamics of an image pure gauge theory of scale image is lacking an explanation of the (Gaussian) spatial curvature perturbations needed to seed the formation of large-scale structure after inflation. In this work it is demonstrated how fundamentally charged fermions of mass image, whose approximate chiral symmetry is spontaneously broken during inflation, can cure this shortcoming. The associated gas of weakly interacting pseudo Nambu–Goldstone bosons (PNGB) undergoes Bose–Einstein (BE) condensation well before the end of inflation. This causes the occurence of condensed light scalar fields effectively acting as a curvaton. Fermions may also be charged under a gauge group G with a weak coupling g. Since fermions charged under image are confined after inflation the decay of Nambu–Goldstone bosons, which reside in the condensates and in the PNGB radiation generated at reheating, is mainly into fermions solely charged under G. The associated decay rate Γ is estimated using PCAC and large image counting. PNGB decay takes place during radiation domination after cosmological scales have entered the horizon. Neglecting the effects of the spontaneous breaking of G induced by the BE condensation, it is demonstrated that the observed spectrum of spatial curvature perturbations image is compatible with image, a ratio image of curvaton to radiation energy at PNGB decay, and a curvaton effective equation of state image.
