New one-parametric extension of the Starobinsky inflationary model

Abstract

Abstract We propose a one-parametric extension of the Starobinsky R + R 2 model by adding the R + m 2 β 2 3 / 2 term. The parameter m is the inflaton mass, which is determined in the same way as in the Starobinsky model, and β is a dimensionless constant. Using the Einstein frame and the scalar field potential, we get the inflationary parameters of the model proposed. The value of the tensor-to-scalar ratio r can be significantly larger than in the Starobinsky model. The considered inflationary model is in a good agreement with the current observational data. The corresponding scalar field potential is a polynomial of the exponential function.