No-scale supergravity realization of the Starobinsky model of inflation

Phys Rev Lett. 2013 Sep 13;111(11):111301. doi: 10.1103/PhysRevLett.111.111301. Epub 2013 Sep 9.

Abstract

We present a model for cosmological inflation based on a no-scale supergravity sector with an SU(2,1)/SU(2)×U(1) Kähler potential, a single modulus T, and an inflaton superfield Φ described by a Wess-Zumino model with superpotential parameters (μ, λ). When T is fixed, this model yields a scalar spectral index n(s) and a tensor-to-scalar ratio r that are compatible with the Planck measurements for values of λ≃μ/3M(P). For the specific choice λ=μ/3M(P), the model is a no-scale supergravity realization of the R+R2 Starobinsky model.