Related papers: Gravitational Waves from Double Hybrid Inflation

We propose a simple realization of hybrid inflation in supergravity, which does not require any unnaturally small parameters. Inflation in this scenario is relatively short, and inflationary density perturbations fall down on large scales,…

We investigate the viability of a two-stage inflationary scenario in the context of supergravity, so as to resolve the problem of initial conditions for hybrid inflation. We allow for non-renormalizable terms in the superpotential and…

During hybrid inflation, the slowly-rolling inflaton field has a significant coupling to the trigger field which is responsible for most of the potential. Barring a fine-tuned accidental cancellation, this coupling induces a minimal…

We show that, for a given fixed value of the number of e-folds of the homogeneous solution, inflation succeeds with order unity inhomogeneities in the initial conditions above a characteristic value of the tensor-to-scalar ratio $r$. In…

We treat a model in which tensor perturbations of de~Sitter spacetime, represented as a spatially flat model, are modified by the effects of the vacuum fluctuations of a massless conformally invariant field, such as the electromagnetic…

Inflation is often described through the dynamics of a scalar field, slow-rolling in a suitable potential. Ultimately, this inflaton must be identified as the expectation value of a quantum field, evolving in a quantum effective potential.…

We carry out numerical investigations of the dynamics and perturbations in the Nflation model of Dimopoulos et al. (2005). This model features large numbers of scalar fields with different masses, which can cooperate to drive inflation…

We argue that all the necessary ingredients for successful inflation are present in the flat directions of the Minimally Supersymmetric Standard Model. We show that out of many gauge invariant combinations of squarks, sleptons and Higgses,…

We consider the extension of the supersymmetric Pati-Salam model introduced in order to solve the b-quark mass problem in supersymmetric theories with Yukawa unification, universal boundary conditions and mu>0. This model naturally leads to…

We investigate the scalar and vector modes arising from cosmological perturbations within the framework of an inflationary scenario driven by an antisymmetric tensor field, minimally coupled to gravity. After eliminating gauge artifacts,…

Using a large N sigma model approximation we explicitly calculate the power spectrum of gravitational waves arising from a global phase transition in the early universe and we confirm that it is scale invariant, implying an observation of…

The super-inflationary phase is predicted by the Loop Quantum Cosmology. In this paper we study the creation of gravitational waves during this phase. We consider the inverse volume corrections to the equation for the tensor modes and…

In the lights of current BICEP2 observations accompanied with the PLANCK satellite results, it has been observed that the simple single field chaotic inflationary models provide a good agreement with their spectral index n_s and large…

We investigate a topological inflation model in supergravity. By means of numerical simulations, it is confirmed that topological inflation can take place in supergravity. We also show that the condition for successful inflation depends not…

If a sizeable tensor-to-scalar ratio ~0.1 turns out to be detected and a negative running of the scalar spectral index ~0.01 is significantly required by the data, the vast majority of single field models of inflation will be ruled out. We…

It is believed that the recent detection of large tensor perturbations strongly favors the inflation scenario in the early universe. This common sense depends on the assumption that Einstein's general relativity is valid at the early…

We consider a class of well motivated supersymmetric models of F-term hybrid inflation (FHI) which can be linked to the supersymmetric grand unification. The predicted scalar spectral index n_s cannot be smaller than 0.97 and can exceed…

The magnitude of B-mode polarization in the cosmic microwave background as measured by BICEP2 favours models of chaotic inflation with a quadratic $m^2 \phi^2/2$ potential, whereas data from the Planck satellite favour a small value of the…

We consider hybrid inflation for small couplings of the inflaton to matter such that the critical value of the inflaton field exceeds the Planck mass. It has recently been shown that inflation then continues at subcritical inflaton field…

We revisit the possibility of producing observable tensor modes through a continuous particle production process during inflation. Particularly, we focus on the multi-field realization of inflation where a spectator pseudo-scalar $\sigma$…