Related papers: $\phi^2$ Inflation at its Endpoint
In the present work we study a warm inflationary model defined by a quasi-exponential inflaton potential and an inflaton decay rate proportional to the Hubble rate. The model is characterized by three free parameters. We compute the power…
The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest…
A simple realization of inflation consists of adding the following operators to the Einstein-Hilbert action: (partial phi)^2, lambda phi^4, and xi phi^2 R, with xi a large non-minimal coupling. Recently there has been much discussion as to…
We derive a generalized expressions for the scalar power spectrum and the observational parameters of inflation (the scalar spectral index $n_{\rm s}$ and the tensor-to-scalar ratio $r$) for several single field scalar models minimally…
We show that the prediction for the primordial tensor power spectrum cannot be modified at leading order in derivatives. Indeed, one can always set to unity the speed of propagation of gravitational waves during inflation by a suitable…
We re-examine the original model of Natural inflation, in which the inflaton is a pseudo Nambu-Goldstone boson with potential of the form $ V(\phi) = \Lambda^4 [1 \pm \cos(\phi/f)]$, in light of recent data. We find that the model is alive…
Polynomial inflation is a very simple and well motivated scenario. A potential with a concave ``almost'' saddle point at field value $\phi = \phi_0$ fits well the cosmic microwave background (CMB) data and makes testable predictions for the…
A new class of inflation models within the context of G-inflation is proposed, in which the standard model Higgs boson can act as an inflaton thanks to Galileon-like non-linear derivative interaction. The generated primordial density…
The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest…
We revisit the inflection point inflation with an extended discussion to large field values and consider the reheating effects on the inflationary predictions. Parametrizing the reheating dynamics in terms of the reheating temperature and…
We derive the reconstruction formulae for the inflation model with the non-minimal derivative coupling term. If reconstructing the potential from the tensor-to-scalar ratio, we could obtain the potential without using the high friction…
In the present work we study the consequences of considering an inflationary universe model in which the Hubble rate has a quasi-exponential dependence in the inflaton field, given by $H(\phi)=H_{inf}\exp…
We show how short inflation naturally arises in a non-minimal gravity theory with a scalar field without any potential terms. This field drives inflation solely by its derivatives, which couple to the matter only through the combination…
The equivalence between $f(R)$ and scalar-tensor theories is revisited, we consequently explored different $f(R)$ models. After consideration of specific definition of the scalar field, we derived the potentials $V(\phi)$ for each $f(R)$…
We present here the effective theory of inflation `a la Ginsburg-Landau in which the inflaton potential is a polynomial. The slow-roll expansion becomes a systematic 1/N expansion where N ~ 60. The spectral index and the ratio of…
We revisit the quadratic inflationary potential by introducing a minimal higher-order correction obtained through a simple field redefinition, leading to the potential V(chi) = (1/2) m^2 * (chi - (gamma/14) * chi^7)^2. While the uncorrected…
Nonminimally coupled inflation models based on a nonminimal coupling $\xi \phi^{2} R$ and a $\phi^{4}$ potential are in excellent agreement with the scalar spectral index observed by Planck. Here we consider the modification of these models…
In this paper we will analyse the constraints on a sub-Planckian excursion of a single inflaton field, which would yield a large tensor to scalar ratio, while explaining the temperature anisotropy of the cosmic microwave background (CMB)…
We clarify inflaton models by considering them as effective field theories in the Ginzburg-Landau spirit.In this new approach, the precise form of the inflationary potential is constructed from the present WMAP data, and a useful scheme is…
The formalism of stochastic inflation is a powerful tool for analyzing the backreaction of cosmological perturbations, and making precise predictions for inflationary observables. We demonstrate this with the simple $m^2\phi^2$ model of…