Maximal supersymmetry and B-mode targets

Extending the work of Ferrara and one of the authors [1], we present dynamical cosmological models of α-attractors with plateau potentials for 3α = 1, 2, 3, 4, 5, 6, 7. These models are motivated by geometric properties of maximally supersymmetric theories: M-theory, superstring theory, and maximal N = 8 supergravity. After a consistent truncation of maximal to minimal supersymmetry in a seven-disk geometry, we perform a two-step procedure: 1) we introduce a superpotential, which stabilizes the moduli of the seven-disk geometry in a supersymmetric minimum, 2) we add a cosmological sector with a nilpotent stabilizer, which breaks supersymmetry spontaneously and leads to a desirable class of cosmological attractor models. These models with n_s consistent with observational data, and with tensor-to-scalar ratio r ≈ 10⁻² − 10⁻³, provide natural targets for future B-mode searches. We relate the issue of stability of inflationary trajectories in these models to tessellations of a hyperbolic geometry.