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Universality of multi-field α-attractors

2018; Institute of Physics; Volume: 2018; Issue: 04 Linguagem: Inglês

10.1088/1475-7516/2018/04/028

1475-7516

Ana Achúcarro, Рената Каллош, Andrei Linde, Dong-Gang Wang, Yvette Welling,

Nonlinear Dynamics and Pattern Formation

We study a particular version of the theory of cosmological α-attractors with α=1/3, in which both the dilaton (inflaton) field and the axion field are light during inflation. The kinetic terms in this theory originate from maximal =4 superconformal symmetry and from maximal =8 supergravity. We show that because of the underlying hyperbolic geometry of the moduli space in this theory, it exhibits double attractor behavior: their cosmological predictions are stable not only with respect to significant modifications of the dilaton potential, but also with respect to significant modifications of the axion potential: ns≃1−2/N, r≃4/N2. We also show that the universality of predictions extends to other values of α ≲ (1) with general two-field potentials that may or may not have an embedding in supergravity. Our results support the idea that inflation involving multiple, not stabilized, light fields on a hyperbolic manifold may be compatible with current observational constraints for a broad class of potentials.