相关论文: Stability of the 3-form field during inflation

We consider the 3-form field, which has been considered as a candidate for realizing inflation, coupled to a scalar field which models the relativistic matter particles produced during the reheating epoch. We have investigated the stability…

Many models of inflation driven by vector fields alone have been known to be plagued by pathological behaviors, namely ghost and/or gradient instabilities. In this work, we seek a new class of vector-driven inflationary models that evade…

We have investigated if the vector field can give rise to an accelerating phase in the early universe. We consider a timelike vector field with a general quadratic kinetic term in order to preserve an isotropic background spacetime. The…

We investigate the possibility of inflation with models of antisymmetric tensor field having minimal and nonminimal couplings to gravity. Although the minimal model does not support inflation, the nonminimal models, through the introduction…

Anisotropic and isotropic slow-roll inflation supported by n-forms are sought. Canonical field strengths and their duals are taken into account, and they are allowed to have a potential and also, when necessary for slow-roll, a nonminimal…

A setting constituted by $\mathbb{N}$ 3-form fields, without any direct interaction between them, minimally coupled to gravity, is introduced in this paper as a framework to study the early evolution of the universe. We focus particularly…

We propose a new framework for multi-field inflation in which a nearly constant potential energy is maintained during inflation before decreasing rapidly, in a manner analogous to a classical top spinning upright for a long time before…

We summarize our work on a consistency condition for inflation in two-field cosmological models, in the regime of rapid turn and third-order slow roll. To ensure a sustained inflationary period of this type, one needs to satisfy a certain…

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…

We consider a variant of Hybrid Inflation, where inflation is driven by two interacting scalar fields, one of which has a `Mexican hat' potential and the other a quartic potential. Given the appropriate initial conditions one of the fields…

The $SL(2,\mathbb{Z})$ invariant $\alpha$-attractor models have plateau potentials with respect to the inflaton and axion fields. The potential in the axion direction is almost exactly flat during inflation, hence, the axion field remains…

Inflation driven by a single, minimally coupled, slowly rolling field generically yields a negligible primordial non-Gaussianity. We discuss two distinct mechanisms by which a non-trivial potential can generate large non-Gaussianities.…

We study the robustness of single-field inflation against inhomogeneities. We derive a simple analytic criterion on the shape of the potential for successful inflation in the presence of inhomogeneities, and demonstrate its validity using…

We investigate a standard minimally-coupled scalar-field inflationary scenario, which is based on a new potential, with suitably generalized plateau features, that leads to extra small tensor-to-scalar ratios. In particular, we consider a…

Heavy scalar fields can undergo an instability during inflation as a result of their kinetic couplings with the inflaton. This is known as the geometrical destabilization of inflation, as it relies on the effect of the negative curvature of…

We explore the stability properties of multi-field solutions of assisted inflation type, where several fields collectively evolve to the same configuration. In the case of noninteracting fields, we show that the condition for such solutions…

We examine a wide class of multi-field inflationary models based on fields that decay or stabilize during inflation in a staggered fashion. The fields driving assisted inflation are on flat, short stretches, before they encounter a sharp…

Westudythebehaviourofisocurvatureperturbationsinnon-linearsigmamodels which naturally emerge in supergravity and string inflationary scenarios. We focus on the case of negatively curved field manifolds which can potentially lead to a…

Most models of inflation have small parameters, either to guarantee sufficient inflation or the correct magnitude of the density perturbations. In this paper we show that, in supersymmetric theories with weak scale supersymmetry breaking,…

The calculation of scalar gravitational and matter perturbations during multiple-field inflation valid to first order in slow roll is discussed. These fields may be the coordinates of a non-trivial field manifold and hence have non-minimal…