Related papers: Slow and Safe Gravitinos
In this note we study supergravity models with constrained superfields. We construct a supergravity framework in which all (super)symmetry breaking dynamics happen in vacuum with naturally (or otherwise asymptotically) vanishing energy.…
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…
When inflation is driven by a pseudo-scalar field \chi coupled to vectors as \alpha/4 \chi F \tilde F, this coupling may lead to a copious production of gauge quanta, which in turns induces non-Gaussian and non-scale invariant corrections…
Inflationary models driven by a large number of axion fields are discussed in the context of type IIB compactifications with N=1 supersymmetry. The inflatons arise as the scalar modes of the R-R two-forms evaluated on vanishing two-cycles…
In gravity mediated models and in particular in models with strongly stabilized moduli, there is a natural hierarchy between gaugino masses, the gravitino mass and moduli masses: $m_{1/2} \ll m_{3/2} \ll m_{\phi}$. Given this hierarchy, we…
Inflation may have been driven by a component which violated the Null-Energy Condition, thereby leading to {\it super inflation}. We provide the formalism to study cosmological perturbations when such a component is described by a scalar…
We argue that the mass of the inflaton can be much smaller than the Hubble constant in supergravity models in which inflation is driven by D--terms and not F--terms. We investigate a supergravity toy model which leads to hybrid inflation…
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 construct new models of inflation and spontaneous supersymmetry breaking in de Sitter vacuum, with a single chiral superfield, where inflaton is the superpartner of the goldstino. Our approach is based on hyperbolic K\"ahler geometry,…
The excessive production of gravitinos in the early universe destroys the successful predictions of nucleosynthesis. The thermal generation of gravitinos after inflation leads to the bound on the reheating temperature, T_{RH}< 10^9 GeV.…
We review the emergence and fate of goldstinos in different frameworks. First, we consider a super-Higgs mechanism when supersymmetry breaking is induced by neither an F-term nor a D-term but related to a more general stress energy-momentum…
It has been shown that hybrid inflation may end with the formation of non-topological solitons of inflaton field. As a first step towards a fully realistic picture of the post-inflation era and reheating in supersymmetric hybrid inflation…
It was argued in \cite{DallAgata:2022abm} that the Volkov-Akulov (VA) model as well as similar models in supergravity and the related KKLT model in string theory, suffer from tachyonic instabilities due to goldstino condensation. The…
We study the production of gravitinos during the preheating era after inflation by means of the non-perturbative Bogolyubov technique. Considering only the helicity $\pm 3/2$ states, the problem is reduced to the simpler Dirac fermions…
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 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 study symmetry breaking and topological defects in a supersymmetric model with gauge group $\text{U}(2)$, which can be identified with the right-handed part $\text{SU}(2)_R \times \text{U}(1)_{B-L}$ of an extended electroweak symmetry of…
Constraints on the required flatness of the scalar potential $V(\phi)$ for a cousin-model to extended inflation are studied. It is shown that, unlike earlier results, Induced-gravity Inflation can lead to successful inflation with a very…
The motion of a pseudo-scalar field $X$ during inflation naturally induces a significant amplification of the gauge fields to which it is coupled. The amplified gauge fields can source characteristic scalar and tensor primordial…
We study the supergravity hybrid inflation model of Ref.[1] in the presence of a modulus field. The eta-problem is solved by a shift symmetry for the inflaton, which protects the inflaton mass even in the presence of the modulus field.…