English
Related papers

Related papers: Primordial Non-Gaussianity from G-inflation

200 papers

In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$…

High Energy Physics - Theory · Physics 2023-07-18 Alexey S. Koshelev , K. Sravan Kumar , Alexei A. Starobinsky

This is a pedagogical review on primordial non-Gaussianities from inflation models. We introduce formalisms and techniques that are used to compute such quantities. We review different mechanisms which can generate observable large…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-10 Xingang Chen

The simplest models of inflation predict small non-gaussianities and a featureless power spectrum. However, there exist a large number of well-motivated theoretical scenarios in which large non-gaussianties could be generated. In general,…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-11 Stefano Gariazzo , Laura Lopez-Honorez , Olga Mena

Primordial non-Gaussianity encodes vital information of the physics of the early universe, particularly during the inflationary epoch. To explore the local-type primordial non-Gaussianity $f_{\mathrm{NL}}$, we study the anisotropies in…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-25 Jun-Peng Li , Sai Wang , Zhi-Chao Zhao , Kazunori Kohri

The late-time effect of primordial non-Gaussianity offers a window into the physics of inflation and the very early Universe. In this work we study the consequences of a particular class of primordial non-Gaussianity that is fully…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 G. A. Peña , G. N. Candlish

We study a model where two scalar fields, that are subdominant during inflation, decay into radiation some time after inflation has ended but before primordial nucleosynthesis. Perturbations of these two curvaton fields can be responsible…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hooshyar Assadullahi , Jussi Valiviita , David Wands

We compute the three-point correlation function of primordial scalar density perturbations in a general single-field inflationary scenario, where a scalar field phi has a direct coupling with the Ricci scalar R and the Gauss-Bonnet term GB.…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Antonio De Felice , Shinji Tsujikawa

We extend the \delta N formalism so that it gives all of the stochastic properties of the primordial curvature perturbation \zeta if the initial field perturbations are gaussian. The calculation requires only the knowledge of some family of…

Astrophysics · Physics 2011-06-08 David H. Lyth , Yeinzon Rodriguez

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid

We consider a member of the family of scalar-tensor theories of Inflation - the so-called Horndeski model for Inflation, for which we calculate the non-Gaussianity (NG) and the power spectrum of curvature perturbations. We concentrate on…

General Relativity and Quantum Cosmology · Physics 2021-07-29 Avneet Singh

We analyze the non-Gaussianity for primordial curvature perturbations generated in multi-scalar slow-roll inflation model including the model with non-separable potential by making use of $\delta N$ formalism. Many authors have investigated…

Astrophysics · Physics 2009-06-23 Shuichiro Yokoyama , Teruaki Suyama , Takahiro Tanaka

We characterise the primordial perturbations produced due to both inflaton and curvaton fluctuations in models where the curvaton has a quadratic, cosine or hyperbolic potential, and the inflaton potential is characterised by the usual…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 José Fonseca , David Wands

Cosmic inflation provides a mechanism for generating the early density perturbations that seeded the large-scale structures we see today. Primordial non-Gaussianity is among the most promising of few observational tests of physics at this…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-10 Marilena LoVerde , Simone Ferraro , Kendrick M. Smith

We present a class of models in which the primordial metric fluctuations do not necessarily obey Gaussian statistics. These models are realizations of mechanisms in which non-Gaussianity is first generated by a light scalar field and then…

Astrophysics · Physics 2009-11-11 Francis Bernardeau , Tristan Brunier , Jean-Philippe Uzan

We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…

Astrophysics · Physics 2010-10-27 Thorsten Battefeld , Richard Easther

It is possible that the primordial non-Gaussianity is dominated by the higher order terms, such as that set by $g_{NL}$, not $f_{NL}$. In this paper we derive the spectral index and running of $g_{NL}$ from a single isocurvature scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Qing-Guo Huang

We analyze primordial non-Gaussianity in single field inflationary models when the tensor/scalar ratio is large. Our results show that detectable levels of non-Gaussianity $f_{NL} \sim 50$ are still possible in the simplest class of models…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-19 Guido D'Amico , Matthew Kleban

We study primordial non-gaussianity in supersolid inflation. The dynamics of supersolid is formulated in terms of an effective field theory based on four scalar fields with a shift symmetric action minimally coupled with gravity. In the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 Marco Celoria , Denis Comelli , Luigi Pilo , Rocco Rollo

We present primordial non-Gaussianity predictions from a new high-precision code for simulating axion-U(1) inflation on a discrete lattice. We measure the primordial scalar curvature power spectrum and bispectrum from our simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Drew Jamieson , Angelo Caravano , Eiichiro Komatsu

We use the delta N-formalism to describe the leading order contributions to the primordial power spectrum, bispectrum and trispectrum in multiple-field models of inflation at leading order in a perturbative expansion. In slow-roll models…

Astrophysics · Physics 2008-11-26 Christian T. Byrnes , Misao Sasaki , David Wands