Supergravity inflation with broken shift symmetry and large tensor-to-scalar ratio

Abstract

We propose a class of inflation models with potentialV(ϕ) = αϕnexp(−βmϕm).We show that such kind of inflaton potentials can be realizedin supergravity theory with a small shift symmetry breakingterm in the K"ahler potential. We find that the models with(m = 1,n = 1), (m = 1,n = 2), (m = 2,n = 1), and (m = 2,n = 3/2)can easily accommodate the Planck results. In particular, thetensor-to-scalar ratio is larger than 0.01 in the 1σ region.Thus, these models generate the typical large field inflation,and can be tested at the future Planck and QUBIC experiments.