Chaotic Inflationary Universe in Rastall Gravity

Abstract

We study Linde's chaotic inflation in Rastall gravity with a homogeneous scalar field. In Einstein's general theory of relativity (GR) Linde obtained chaotic scenario which emerged from chaotic distribution of scalar field satisfying a limiting value of the initial scalar field \phi_o > 3 M_P which lies in the quantum gravity. The upper limit on the initial scalar field is obtained for a sufficient inflation to encompass the present universe. In the Rastall gravity the upper limit is reduced depending on the Rastall parameter \gamma <1. The upper limit on \phi_o is found to increases for 1<\gamma <\frac{3}{2}. In the later case sufficient inflation is not permitted and the role of curvaton field is explored for an acceptable early chaotic inflation.