A microscopic model for inflation from supersymmetry breaking

Abstract

We have proposed recently a framework for inflation driven by supersymmetry breaking with the inflaton being a superpartner of the goldstino, that avoids the main problems of supergravity inflation, allowing for: naturally small slow-roll parameters, small field initial conditions, absence of a (pseudo)scalar companion of the inflaton, and a nearby minimum with tuneable cosmological constant. It contains a chiral multiplet charged under a gauged R-symmetry which is restored at the maximum of the scalar potential with a plateau where inflation takes place. The effective field theory relies on two phenomenological parameters corresponding to corrections to the Kähler potential up to second order around the origin. The first guarantees the maximum at the origin and the second allows the tuning of the vacuum energy between the F- and D-term contributions. Here, we provide a microscopic model leading to the required effective theory. It is a Fayet–Iliopoulos model with two charged chiral multiplets under a second R-symmetry coupled to supergravity. In the Brout–Englert–Higgs phase of this , the gauge field becomes massive and can be integrated out in the limit of small supersymmetry breaking scale. In this work, we perform this integration and we show that there is a region of parameter space where the effective supergravity realises our proposal of small field inflation from supersymmetry breaking consistently with observations and with a minimum of tuneable energy that can describe the present phase of our Universe.

Aspects of gauged R symmetry in SU(1,1)/U(Aldabergenov1 2020Phys. Rev. D4070View full textAdd to dashboardCite

“…6 The situation is somewhat similar to the construction of Refs. [18,19] where the Kähler potential is canonical (plus a quartic term), while the superpotential is linear due to the requirement of local R-symmetry. In this model viable hilltop inflation becomes possible only after including certain higher-order corrections to the Kähler potential.…”

Challenges in Supersymmetric Cosmology

“…We now explain the notation. For details, see [26]. An action integral with d 4 xd 4 θ in the third line of (31) is called the D-type action.…”

“…"The compensators C, C are chiral primaries of charges (1, 2/3), and anti-chiral primary of charges (1, −2/3), respectively. To guarantee gauge invariance, we assign U(1) m charges to the compensators as" [26] C → e i(q…”

“…The simplest way to achieve this is by extending the symmetry of the UV theory from U(1) m to U(1) m × U(1) and assuming that the additional U(1) does not take part in the integrating out process and survives as the gauged R-symmetry of the low-energy theory. As we summarize in Table 1 [26]. Table 1.…”

“…In order to having a local maximum at the origin, we need to satisfy the constraint A 2 > 0. According to the signs of ∆ and of the scalar component c, we can divide the domain in two-dimensional parameter space (v, x) in which A 2 is positive into four regions [26]:…”