Marco Scalisi (Van Swinderen Institute - University of Groningen, Netherlands)
The Planck value of the spectral index can be interpreted as ns=1−2/N in terms of the number of e-foldings N. An appealing explanation for this phenomenological observation is provided by α-attractors: the inflationary predictions of these supergravity models are fully determined by the curvature of the Kahler manifold. We provide a unified description of cosmological α-attractors and late-time acceleration. Our construction involves two superfields playing distinctive roles: one is the dynamical field and its evolution determines inflation and dark energy, the other is nilpotent and responsible for a landscape of vacua and supersymmetry breaking. We prove that the attractor nature of the theory is enhanced when combining the two sectors: cosmological attractors are very stable with respect to any possible value of the cosmological constant and, interestingly, to any generic coupling of the inflationary sector with the field responsible for uplifting.