Related papers: Density fluctuations in one-field inflation

We discuss a universal bound on any excitation of heavy fields during inflation: the ratio of the heavy field's energy density to the one driving inflation must be less than the maximally allowed relative amplitude of oscillations in the…

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

We compute one-loop corrections to the power spectrum of the curvature perturbation in single-field slow-roll inflation arising from gravitons and inflaton interactions. The quantum corrections due to gravitons to the power spectrum of the…

A field kinetic coupling with the Einstein tensor leads to a gravitationally enhanced friction during inflation, by which even steep potentials with theoretically natural model parameters can drive cosmic acceleration. In the presence of…

We develop a numerical statistical method to study linear cosmological fluctuations in inflationary scenarios with multiple fields, and apply it to an ensemble of six-field inflection point models in string theory. The latter are concrete…

In the context of single field inflation, models with a quadratic potential and models with a natural potential with subplanckian decay constant are in tension with the Planck data. We show that, when embedded in a two-field model with an…

Many statistics available to constrain non-Gaussianity from inflation are simplest to use under the assumption that the curvature correlation functions are hierarchical. That is, if the n-point function is proportional to the (n-1) power of…

We present the first quantum field theory model of inflation that is renormalizable in the matter sector, with a super-Hubble inflaton mass and sub-Planckian field excursions, which is thus technically natural and consistent with a…

We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic…

We study primordial perturbations from hyperinflation, proposed recently and based on a hyperbolic field-space. In the previous work, it was shown that the field-space angular momentum supported by the negative curvature modifies the…

We show that density perturbations seeded by the inflaton can be suppressed when having additional light degrees of freedom contributing to the production of perturbations. The inflaton fluctuations affect the light field dynamics by…

We generalize the consistency condition for the three-point function in single field inflation to the case of dissipative, multi-field, single-clock models. We use the recently introduced extension of the effective field theory of inflation…

We reexamine inflation due to a constrained inflaton in the model of a complex scalar. Inflaton evolves along a spiral-like valley of special scalar potential in the scalar field space just like single field inflation. Sub-Planckian…

We show the existence of a general mechanism by which heavy scalar fields can be destabilized during inflation, relying on the fact that the curvature of the field space manifold can dominate the stabilizing force from the potential and…

We revisit an extension of the well-known formalism for gauge-invariant scalar metric fluctuations, to study the spectrums for both, the inflaton and gauge invariant (scalar) metric fluctuations in the framework of a single field…

We study two-field inflation derived from a single complex scalar field with a nonzero vacuum expectation value. The dynamics of inflation are governed by two parameters, the vacuum expectation value and the mass parameter of the phase…

We propose a model of inflation with a suitable potential for a single scalar field which falls in the wide class of hilltop inflation. We derive the analytical expressions for most of the physical quantities related to inflation and show…

We study the realization of slow-roll inflation in $\mathcal N = 1$ supergravities where inflation is the result of the evolution of a single chiral field. When there is only one flat direction in field space, it is possible to derive a…

In an alternative mechanism recently proposed, adiabatic cosmological perturbations are generated at the decay of the inflaton field due to small fluctuations of its coupling to matter. This happens whenever the coupling is governed by the…

Reheating is a transition era after the end of inflation, during which the inflaton is converted into the particles that populate the Universe at later times. No direct cosmological observables are normally traceable to this period of…