The recent detection by the BICEP2 collaboration of a high level of tensor modes seems to exclude the Starobinsky model of inflation. In this paper we show that this conclusion can be avoided: it is enough to embed the Starobinsky model in supergravity and identify the inflaton field with the imaginary (instead of the real) part of the chiral scalaron multiplet in its formulation. The Starobinsky model then becomes the chaotic quadratic model with shift symmetry during infation and is in perfect agreement with the current data.
Address
Département de Physique Théorique
Université de Genève
24, quai Ernest Ansermet
1211 Genève 4
Switzerland
Directions & contact