Related papers: Inflation models and observation
Models of cosmic inflation posit an early phase of accelerated expansion of the universe, driven by the dynamics of one or more scalar fields in curved spacetime. Though detailed assumptions about fields and couplings vary across models,…
In single-field inflationary models with a low sound speed, the orthogonal shape of the primordial bispectrum arises due to partial cancellations between equilateral-type shapes. This fact allows for a speed of sound c_s as low as about…
In addition to generating the appropriate perturbation power spectrum, an inflationary scenario must take into account the need for inflation to end subsequently. In the context of single-field inflation models where inflation ends by…
We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct…
We consider trapped inflation in a higher dimensional field space: particle production at a dense distribution of extra species points leads to a terminal velocity at which inflation can be driven in steep potentials. We compute an…
Inflation during rapid oscillation of a scalar field in non-minimal derivative coupling model is discussed. Cosmological perturbations originated in this stage are studied and consistency of the results with observational constraints coming…
With a scalar field non-minimally coupled to curvature, the underlying geometry and variational principle of gravity - metric or Palatini - becomes important and makes a difference, as the field dynamics and observational predictions…
An inflationary model in the framework of noncommutative space-time may generate a nontrivial running of the scalar spectral index, but usually induces a large tensor-to-scalar ratio simultaneously. With the latest observational data from…
After the release of the PLANCK data, it is evident that inflationary paradigm has stood the test of time. Even though, it is difficult to realise inflationary paradigm in a particle physics model as the present observations have ruled out…
Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models…
The detection of a primordial stochastic gravitational wave background has the potential to reveal unprecedented insights into the early universe, and possibly into the dynamics of inflation. Generically, UV-complete inflationary models…
How sensitive are the predictions of inflation to pre-inflationary conditions when the number of efolds of inflation is not too large? In an attempt to address this question, we consider a simple model where the inflationary era is preceded…
We study the emergence of quantum entanglement in multi-field inflation. In this scenario, the perturbations of one field contribute to the observable curvature perturbation, while multi-field dynamics with the other fields affect the…
We construct a multi-field inflationary model consisting of multiple K\"ahler moduli derived from type IIB string compactification in the large volume limit. The model consists of both heavy and light fields, with the former being frozen…
Primordial perturbations with wavelengths greater than the observable universe shift the effective background fields in our observable patch from their global averages over the inflating space. This leads to a landscape picture where the…
We study the bispectrum of the curvature perturbation on uniform energy density hypersurfaces in models of inflation with two scalar fields evolving simultaneously. In the case of a separable potential, it is possible to compute the…
We present two families of multi-field potentials that support inflation while satisfying the refined de Sitter and the distance swampland conjectures. Both families feature Planck-compatible phenomenology. The first is a helix-type…
We review the connection between inflationary models and observations and concentrate to describe models based on softly broken supersymmetry, in particular running mass models, and their predictions. We then present a fit of the spectral…
We study the background and perturbations in $k$-essence inflation models and show that a general $k$-essence exhibits a simple scaling property. In particular, we study two classes of $k$-inflation models with the potential characterized…
We construct an inflationary model that is consistent with both large non-Gaussianity and a running spectral index. The scenario of modulated inflation suggests that modulated perturbation can induce the curvature perturbation with a large…