Toward pole inflation and attractors in supergravity : Chiral matter field inflation

Abstract

In string-inspired supergravity theory, K\"{a}hler metric of chiral matter fields often has a pole. Such K\"{a}hler metric is interesting from the viewpoint of the framework of the pole inflation, where the scalar potential can be stretched out to be flat around the pole for a canonically normalized field and inflation can be realized. However, when K\"{a}hler metric has a pole, the scalar potential can also have a pole at the same point in supergravity theory. We study such supergravity models with the pole, and provide numerical analysis of inflationary dynamics and resultant density perturbation. In contrast with usual pole inflation models, inflation in this supergravity based model occurs not on the pole but region apart from the pole. We show that the existence of the pole in the scalar potential is crucial nevertheless. We also examine attractor behavior of our model.