Related papers: On the waterfall behavior in hybrid inflation
We introduce a new method for calculating density perturbations in hybrid inflation which avoids treating the fluctuations of the "waterfall" field as if they were small perturbations about a classical trajectory. We quantize only the…
In this paper the possibility of generating large scale curvature perturbations induced from the entropic perturbations during the waterfall phase transition of standard hybrid inflation model is studied. We show that whether or not…
Hybrid inflation models are especially interesting as they lead to a spike in the density power spectrum on small scales, compared to the CMB, while also satisfying current bounds on tensor modes. Here we study hybrid inflation with $N$…
We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains $\phi^4$ term as well as terms in the original hybrid inflation model. In our model, inflation…
For the original hybrid inflation model, we calculate the power spectrum of curvature perturbations generated during the waterfall, taking into account the contribution of entropic modes. We study the regime where the potential is very…
We analyze the dynamics and observational predictions of supersymmetric hybrid inflation in the warm regime, where dissipative effects are mediated by the waterfall fields and their subsequent decay into light degrees of freedom. This…
For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to…
We revisit two-field hybrid inflation as an effective field theory for low-scale inflation with sub-Planckian scalar field ranges. We focus on a prototype model by Stewart because it allows for a red spectral tilt, which still fits the…
Hybrid inflation faces two well-known problems: the blue spectrum of the non-supersymmetric version of the model and the fine-tuning of the initial conditions of the fields leading to sufficient inflation to account for the standard…
Multiple field models of inflation exhibit new features than single field models. In this work, we study the hierarchy of parameters based on Hubble expansion rate in curved field space and derive the system of flow equations that describe…
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…
We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced…
If the waterfall field of hybrid inflation couples to a U(1) gauge field, the waterfall can generate a statistically anisotropic contribution to the curvature perturbation. We investigate this possibility, generalising in several directions…
We analyze the flow into inflation for generic "single-clock" systems, by combining an effective field theory approach with a dynamical-systems analysis. In this approach, we construct an expansion for the potential-like term in the…
We use the flow equations to determine the different hierarchy Hubble parameters as a function of the number of e-folds for intermediate models in single-field inflation. The obtained expressions allow us to determine at second order in the…
We revisit the recently proposed mechanism of Geometric Inflation. On general grounds, we show that obtaining the right amount of inflation demands an exceedingly large initial energy density. We introduce a scalar field and study the…
We provide an analytical study of the coupling of short and long wavelength fluctuation modes during the initial phase of reheating in two field models like hybrid inflation. In these models, there is - at linear order in perturbation…
For the original hybrid inflation as well as the supersymmetric F-term and D-term hybrid models, we calculate the level of non-gaussianities and the power spectrum of curvature perturbations generated during the waterfall, taking into…
We present an explicit string realisation of a cosmological inflationary scenario we proposed recently within the framework of type IIB flux compactifications in the presence of three magnetised D7-brane stacks. Inflation takes place around…
The general structure of Hybrid Inflation remains a very well-motivated mechanism for lower-scale cosmic inflation in the face of improving constraints on the tensor-to-scalar ratio. However, as originally modeled, the "waterfall" field in…