Related papers: Inflation, Supergravity and Superstrings
We study inflation driven by a slow-rolling inflaton field, characterised by a quadratic potential, and incorporating radiative corrections within the context of supergravity. In this model the energy scale of inflation is not overly…
We investigate the possibility of obtaining inflationary solutions of the slow roll type from a low energy Lagrangian coming from superstrings. The advantage of such an approach is that in these theories the scalar potential has only one…
We analyze F-term hybrid inflation (FHI) within various grand unified theories (GUTs) in the presence of a K\"ahler potential for the inflaton field which parameterizes the K\"ahler manifolds $SU(1,1)/U(1)$ or $SU(2)/U(1)$. We take into…
In this note we demonstrate that chaotic inflation can naturally be realized in the context of an anomaly free minimal gauged supergravity in D=6 which has recently been the focus of some attention. This particular model has a unique…
We review the realization of Starobinsky-type inflation within induced-gravity Supersymmetric (SUSY) and non-SUSY models. In both cases, inflation is in agreement with the current data and can be attained for subplanckian values of the…
We point out that the inflaton spontaneously decays into any gauge bosons and gauginos via the super-Weyl, Kahler and sigma-model anomalies in supergravity, once the inflaton acquires a non-vanishing vacuum expectation value. In particular,…
Inflation is a promising solution to many problems of the standard Big-Bang cosmology. Nevertheless, inflationary models have proved less compelling. In this chapter, we discuss why supersymmetry has led to more natural models of inflation.…
It is known that the Higgs potential becomes flat around the Planck scale under the assumption that the Standard Model is valid up to very high scale. Taking this into account, we revisit the Higgs inflation scenario and find that the…
We comprehensively investigate a chaotic inflation model proposed recently in the framework of supergravity. In this model, the form of K\"ahler potential is determined by a symmetry, that is, the Nambu-Goldstone-like shift symmetry, which…
We construct a two-stage inflationary model which can accommodate early inflation at a scale $\Lambda_1$ as well as a second stage of inflation at $\Lambda_2$ with a single scalar field $\phi$. We use a symmetric potential, valid in a…
We investigate the cosmological inflation in a class of supergravity models that are generalizations of non-supersymmetric $R^2$ models. Although such models have been extensively studied recently, especially after the launch of the PLANCK…
A new shifted hybrid inflationary scenario is introduced which, in contrast to the older one, relies only on renormalizable superpotential terms. This scenario is automatically realized in a concrete extension of the "minimal"…
Shift-symmetry is essential to protect the flatness of the potential, even beyond the super-Planckian vacuum expectation value (VEV) for an inflaton field. The breaking of the shift-symmetry can yield potentials suitable for super-Planckian…
Moduli fields, which parameterize perturbative flat directions of the potential in supersymmetric theories, are natural candidates to act as inflatons. An inflationary potential on moduli space can result if the scale of dynamical SUSY…
This paper discusses models of inflation based on global supersymmetry. It is shown that there are parameter ranges, consisent with observational constraints, for which warm inflation occurs and supergravity effects can be neglected. There…
In the Standard Model, the Higgs potential develops an instability at high field values when the quartic self-coupling runs negative. Large quantum fluctuations during cosmic inflation could drive the Higgs field beyond the potential…
F-term hybrid inflation (FHI) of the hilltop type can generate a scalar spectral index, ns, in agreement with the fitting of the seven-year Wilkinson microwave anisotropy probe data by the standard power-law cosmological model with cold…
We address an issue what kind of tuning realizes a flat potential for inflaton in supergravity. We restrict ourselves to the case that inflationary dynamics is not affected by separate supersymmetry-breaking effects, and consider examples…
We consider models of inflation in supergravity with a shift symmetry. We focus on models with one moduli and one inflaton field. The presence of this symmetry guarantees the existence of a flat direction for the inflaton field. Mildly…
We study the conditions of restoring supersymmetry (SUSY) after inflation in the supergravity-based cosmological models with a single chiral superfield and a quartic stabilization term in the K\"ahler potential. Some new, explicit, and…