Non-minimal two-loop inflation

We investigate the chaotic inflationary model using the two-loop effective potential of a self-interacting scalar field theory in curved spacetime. We use the potential which contains a non-minimal scalar curvature coupling and a quartic scalar self-interaction and which was found in Ref.[1]. We analyze the Lyapunov stability of de Sitter solution and show the stability bound. Calculating the inflationary parameters, we systematically explore the spectral index n(s) and the tensor-to-scalar ratio r, with varying the four parameters, the scalar-curvature coupling xi(0), the scalar quartic coupling lambda(0), the renormalization scale mu and the e-folding number N. It is found that the two-loop correction on n(s) is much larger than the leading-log correction, which has previously been studied in Ref.[2]. We show that the model is consistent with the observation by Planck with WMAP [3,4] and a recent joint analysis of BICEP2 [5]. (C) 2015 The Authors. Published by Elsevier B.V.