Related papers: D-term Inflation and M-theory
We propose a topological inflation model in supergravity. In this model, the vacuum expectation value (VEV) of a scalar field takes a value much larger than the gravitational scale $M_{G} \simeq 2.4 \times 10^{18}$ GeV, which is large…
Two distinct classes of realistic inflationary models consistent with present observations are reviewed. The first example relies on the Coleman-Weinberg potential and is readily realized within the framework of spontaneously broken global…
We propose to address the fine tuning problem of inflection point inflation by the addition of extra vacuum energy that is present during inflation but disappears afterwards. We show that in such a case, the required amount of fine tuning…
We present a model of slow-roll inflation in the context of effective Supergravities arising from string theories. The uplifting of the potential (to generate dS or Minkowski vacua) is provided by the D-term associated to an anomalous U(1),…
Inflection-point inflation is an interesting possibility to realize a successful slow-roll inflation when inflation is driven by a single scalar field with its value during inflation below the Planck mass ($\phi_I \lesssim M_{Pl}$). In…
In the context of single field inflation, models with a quadratic potential and models with a natural potential with subplanckian decay constant are in tension with the Planck data. We show that, when embedded in a two-field model with an…
If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than…
We consider F-term hybrid inflation and supersymmetry breaking in the context of a model which largely respects a global U(1) R symmetry. The Kaehler potential parameterizes the Kaehler manifold with an enhanced U(1)x(SU(1,1)/U(1))…
Global topological defects may account for the large cold spot observed in the Cosmic Microwave Background. We explore possibilities of constructing models of supersymmetric F-term hybrid inflation, where the waterfall fields are globally…
We consider higher-dimensional uniform inflation, in which the extra dimensions expand at the same rate as three-dimensional non-compact space during inflation. We compute the cosmological perturbation in $D+4$ dimensions and derive the…
Supersymmetry-based hybrid inflation models (referred to as `spontaneously broken supersymmetry' by the Planck collaboration) are attractive for several reasons, including the appealing feature that inflation is associated with local gauge…
We study a simple extension of Linde's hybrid inflation model, with the inflaton mass term replaced by the most general renormalizable potential for $\phi$. The unprocessed power spectrum of density perturbations can have two minima and one…
In four dimensional superstring models, the gauge group normally contains extra U(1)s that are broken at a high energy scale. We show that the presence of the extra U(1)s is crucial for the phenomenological viability of string scenarios,…
We propose a class of inflation models with potential V(\phi)=\alpha \phi^n exp(-\beta^m \phi^m). We show that such kind of inflaton potentials can be realized in supergravity theory with a small shift symmetry breaking term in the K\"ahler…
We consider D-term inflation for small couplings of the inflaton to matter fields. Standard hybrid inflation then ends at a critical value of the inflaton field that exceeds the Planck mass. During the subsequent waterfall transition the…
The flat directions LLe and udd within the minimal supersymmetric Standard Model provide all the necessary ingredients for a successful inflation with the right amplitude of the scalar density perturbations, negligible gravity waves and the…
Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of…
Chain Inflation is an alternative to slow roll inflation in which the universe undergoes a series of transitions between different vacua. The density perturbations (studied in this paper) are seeded by the probabilistic nature of tunneling…
Theories where the Planck scale is dynamically generated from dimensionless interactions provide predictive inflationary potentials and super-Planckian field variations. We first study the minimal single-field realisation in the low-energy…
We investigate models in which inflation is driven by an ultraviolet safe and interacting scalar sector stemming from a new class of nonsupersymmetric gauge field theories. These new theories, differently from generic scalar models, are…