R-invariant topological inflation

Abstract

We propose a topological inflation model in the framework of supergravity with R invariance. This topological inflation model is not only free from the initial value problem of the inflaton field but also gives a low reheating temperature, which is favored in supergravity, since in this case the overproduction of gravitinos is avoided. Furthermore, the predicted spectrum of the density fluctuations is found to be generally tilted. This result can be tested by future observations concerning CMB anisotropies and the large scale structure of the universe.