95 citations · 341 across the 10 of their papers we have counts for
10 papers
The curvature perturbation at second order
Mafalda Dias, Joseph Elliston, Jonathan Frazer +2
We give an explicit relation, up to second-order terms, between scalar-field fluctuations defined on spatially-flat slices and the curvature perturbation on uniform-density slices.…
General analytic predictions of two-field inflation and perturbative reheating
Joseph Elliston, Stefano Orani, David J. Mulryne
The observational signatures of multi-field inflation will generally evolve as the Universe reheats. We introduce a general analytic formalism for tracking this evolution through p…
Observable predictions of generalised inflationary scenarios
Joseph Elliston
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 observatio…
What Planck does not tell us about inflation
Joseph Elliston, David J. Mulryne, Reza Tavakol
Planck data has not found the 'smoking gun' of non-Gaussianity that would have necessitated consideration of inflationary models beyond the simplest canonical single field scenario…
Conditions for observable bi and tri-spectra in two-field slow-roll inflation
Joseph Elliston
We find constraints on inflationary dynamics that yield a large local bispectrum and/or trispectrum during two-field slow-roll inflation. This leads to simple relations between the…
The inflationary bispectrum with curved field-space
Joseph Elliston, David Seery, Reza Tavakol
We compute the covariant three-point function near horizon-crossing for a system of slowly-rolling scalar fields during an inflationary epoch, allowing for an arbitrary field-space…
Large trispectrum in two-field slow-roll inflation
Joseph Elliston, Laila Alabidi, Ian Huston +2
We calculate the conditions required to produce a large local trispectrum during two-field slow-roll inflation. This is done by extending and simplifying the 'heatmap' approach dev…
Evolution of non-Gaussianity in multi-scalar field models
Joseph Elliston, David Mulryne, David Seery +1
We study the evolution of non-Gaussianity in multiple-field inflationary models, focusing on three fundamental questions: (a) How is the sign and peak magnitude of the non-linearit…
Evolution of fNL to the adiabatic limit
Joseph Elliston, David J. Mulryne, David Seery +1
We study inflationary perturbations in multiple-field models, for which zeta typically evolves until all isocurvature modes decay--the "adiabatic limit". We use numerical methods t…
Chaotic inflation in modified gravitational theories
Antonio De Felice, Shinji Tsujikawa, Joseph Elliston +1
We study chaotic inflation in the context of modified gravitational theories. Our analysis covers models based on (i) a field coupling with the kinetic energy and a nonm…