Inflationary parameters in renormalization group improved I• 4 theory

Inflation models can be examined by the cosmological observations, WMAP, Planck, BICEP2 and so on. These observations directly constrain the spectral index, n (s) , and the tensor-to-scalar ratio, r. Besides, from a theoretical point of view, it has been shown that any inflation models asymptote a universal attractor in (n (s) ,r) plane for a larger scalar-gravity coupling. In this work we consider a simple chaotic inflation model with a scalar quartic and a scalar-curvature interactions. The quantum corrections are introduced for these interactions through the renormalization group. The inflationary parameters, n (s) and r, are numerically calculated with shifting the bare scalar-gravity coupling xi (0), the quartic scalar bare coupling lambda (0), the renormalization scale mu and the e-folding number N. The Planck data is consistent with the I center dot (4) theory with a finite scalar-curvature coupling. It is found that the renormalization group running induces a non-universal contribution for n (s) and r. It can increase the tensor-to-scalar ratio, r, which is consistent with Planck data so that it may approach the BICEP2 data for a small renormalization scale.