Supersymmetry is the most natural framework for physics above the TeV scale , and the corresponding framework for early-Universe cosmology , including inflation , is supergravity . No-scale supergravity emerges from generic string compactifications and yields a non-negative potential , and is therefore a plausible framework for constructing models of inflation . No-scale inflation yields naturally predictions similar to those of the Starobinsky model based on R + R ^ { 2 } gravity , with a tilted spectrum of scalar perturbations : n _ { s } \sim 0.96 , and small values of the tensor-to-scalar perturbation ratio r < 0.1 , as favoured by Planck and other data on the cosmic microwave background ( CMB ) . Detailed measurements of the CMB may provide insights into the embedding of inflation within string theory as well as its links to collider physics .