IIB String Theory and Sequestered Inflation

Abstract

We develop sequestered inflation models, where inflation occurs along flat directions in supergravity models derived from type IIB string theory. It is compactified on a 𝕋 6 ℤ 2 ×ℤ 2 orientifold with generalized fluxes and O3/O7-planes. At Step I, we use flux potentials which 1) satisfy tadpole cancellation conditions and 2) have supersymmetric Minkowski vacua with flat direction(s). The 7 moduli are split into heavy and massless Goldstone multiplets. At Step II we add a nilpotent multiplet and uplift the flat direction(s) of the type IIB string theory to phenomenological inflationary plateau potentials: 𝜶-attractors with 7 discrete values 3𝜶 = 1, 2, 3, … , 7. Their cosmological predictions are determined by the hyperbolic geometry inherited from string theory. The masses of the heavy fields and the volume of the extra dimensions change during inflation, but this does not affect the inflationary dynamics.

Hybrid cosmological attractors

“…The supergravity version is designed to have the angular fields θ 1 and θ 2 stabilized at their minimum θ 1 = θ 2 = 0 [16,17,[20][21][22]. The class of models describe in equations (3.5), (3.6) can be presented by the following Kähler potential and superpotential (here we call ϕ = ϕ 1 , χ = ϕ 2 and α = α 1 and β = α 2 ).…”

“…3) In models of α-attractors inspired by string theory and M-theory, one may encounter many interacting scalar fields, each of which may have inflaton potentials with different values of α [15][16][17][18][19][20][21][22]. Therefore it is important to explore multi-field α-attractors.…”

BICEP/Keck and Cosmological Attractors

“…So far we presented T-and E-models with a continuous value of α, which at small α reach the attractor point with cosmological predictions depending on the number of e-foldings and α as shown in (2.5). One can implement these models in the minimal N = 1 supergravity, where the parameter 3α is given by 3α = The most interesting B-mode targets in this class of cosmological attractor models are the ones with the discrete values of 3α = 7, 6, 5, 4, 3, 2, 1 [23][24][25][26]. These models of Poincaré disks are inspired by string theory, M-theory and maximal supergravity.…”

Sequestered Inflation

“…In the follow-up investigation [26], we will apply our methods to models where Step I is derived from IIB string theory. There are some specific features of such models.…”