In this work we study two stage models of inflation and the generation of feature in power spectrum. We consider inflationary model with vector field. In order to control the anisotropy coming from vector field we have to tuned the coupling of inflaton and vector fields. This make inflation to be separated into two stage. The confluence point develops a feature in the the power spectrum. Here we consider chaotic and symmetry breaking inflation and study the features due to vector field. Then we consider a general class of models in which inflation is separated into two stages by an intermediate phase with equation of state $\omega$. We show that a double stage inflation can explain the futures in the CMB power spectrum.

IPM Larak Building, School of Astronomy