Related papers: Natural Inflation: status after WMAP 3-year data
We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which…
In models of natural inflation, the inflaton is an axion-like particle. Unfortunately, axion potentials in UV-complete theories appear to be too steep to drive inflation. We show that, even for a steep potential, natural inflation can occur…
The effect of pre-inflation physics on the power spectrum of scalar perturbations is estimated and there is a possibility that the pre-inflation physics explains the Wilkinson Microwave Anisotropy Probe data if the length of inflation is…
A model of natural inflation with an effectively trans-Planckian decay constant can be easily achieved by the "phase locking" mechanism while keeping field values in the effective field theory within the Planck scale. We give detailed…
We study inflation in a random multifield potential, using techniques developed by Marsh et al. The potential is a function of a large number of fields, and we choose parameters so that inflation only occurs in regions where the potential…
We identify a new mechanism in supergravity theories which leads to successful inflation without any need for fine tuning. The simplest model yields a spectrum of density fluctuations tilted away from scale-invariance and negligible…
Recent released WMAP data show a low value of quadrupole in the CMB temperature fluctuations, which confirms the early observations by COBE. In this paper we consider a model of two inflatons with different masses, $V(\phi_1,\phi_2)={1\over…
Inflation is part of the Standard Model of the Universe supported by CMB and large scale structure LSS datasets. This review presents new developments of inflation in three main chapters. (I): The effective theory of inflation a la…
In a previous paper I showed that a classical scalar potential with $V''/V \sim 1$ can be sufficiently flattened by quantum corrections to give rise to slow-roll inflation. In this paper I give a hybrid inflation implementation of that idea…
In the present work we have studied Natural Inflation in the framework of the Randall-Sundrum II brane model (RS-II) in the light of the latest Planck results. Adopting the Randall-Sundrum fine-tuning, the model is characterized by 3…
We describe a method of obtaining the inflationary potential from observations which does not use the slow-roll approximation. Rather, the microwave anisotropy spectrum is obtained directly from a parametrized potential numerically, with no…
We present constraints on canonical single-field inflation derived from WMAP five year, ACBAR, QUAD, BICEP data combined with the halo power spectrum from SDSS LRG7. Models with a non-scale-invariant spectrum and a red tilt n_s < 1 are now…
We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…
Non-abelian discrete gauge symmetries can provide the inflaton with a flat potential even when one takes into account gravitational strength effects. The discreteness of the symmetries also provide special field values where inflation can…
We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for…
We quantify the degree of fine tuning required to achieve an observationally viable period of inflation in the strongly dissipative regime of warm inflation. The ``fine-tuning'' parameter $\lambda$ is taken to be the ratio of the change in…
We consider a gauge inflation model in the simplest orbifold M4 x S1/Z2 with the minimal non-Abelian SU(2) hidden sector gauge symmetry. The inflaton potential is fully radiatively generated solely by gauge self-interactions. Following the…
(Abridged) The WMAP 5-year data strongly limit deviations from the minimal LCDM model. We constrain the physics of inflation via Gaussianity, adiabaticity, the power spectrum shape, gravitational waves, and spatial curvature. We also…
We present a new model of inflation in which the inflaton is the extra component of a gauge field in a 5d theory compactified on a circle. The chief merit of this model is that the potential comes only from non-local effects so that its…
A new model of inflation is described. An unusual form for the inflationary potential is obtained because the inflaton corresponds to a non-trivial path in the configuration space of the two real scalar fields of the model. The model…